A robot vacuum is the rare Black Friday purchase whose running costs are published in advance, in the manual, by the maker. The replacement intervals are printed. The parts are priced on the manufacturer's own store. Almost no deal listing mentions either, because a discount measured against the sticker looks larger than a discount measured against three years of ownership. This guide tears the bill down line by line, using one manufacturer's Canadian store as the worked example, so the same arithmetic can be run on any model discounted on Friday, November 27, 2026.
The full bill, line by line
The example is the Roborock Canada official store, checked on November 4, 2026. The robot is a Qrevo Curv 2 Flow with a multifunctional dock, listed at $999.99 against a crossed-out $1,599.99, with 20,000 Pa suction as listed by the manufacturer, free shipping with the purchase of any Roborock vacuum, returns or replacement within 30 days of delivery, and a 1-year warranty on new products, valid only in Canada. The parts listed on the same store show what ownership bills next.
| Bill line | Price checked November 4, 2026 | Notes |
|---|---|---|
| Robot with multifunctional dock | $999.99 | Crossed-out price on the page: $1,599.99 |
| Dust bags, 6 pack, Qrevo series | $46.99 | About $7.83 per bag |
| Dust bags, 6 pack, Q5 and Q7 families | $32.89 | Bag price depends on the model family, about $5.48 per bag |
| Washable filter, 2 pack | $47.99 | About $24.00 per filter |
| Side brushes replacement | $24.99 | Priced for the Qrevo Curv 2 Flow on its product page |
| Roller mop | $29.99 | Mopping models only |
| Official floor cleaning solution | $27.99 | Optional, and the first line to cut when comparing deals |
Two details in that table do real work. Bag prices are not standard across one brand, let alone across brands, so the bag a specific dock eats has to be priced for that dock. And every line after the first is a recurring purchase with a replacement interval attached, which is where the schedules come in.
Two maintenance schedules, two very different bills
Replacement intervals are set by each manufacturer in its own manuals, and they do not agree with each other. Roborock's Q7 manual sets out one rhythm. Roomba owner guides, including the j8+ guide, set out a faster one.
| Part | Roborock schedule (Q7 manual) | Roomba schedule (owner guides) |
|---|---|---|
| Filter | Clean weekly, replace every 6 to 12 months | Replace every 2 months, or as the app indicates; do not wash the filter |
| Dock dust bag | Replace as needed | Bag holds up to 60 days of debris; replace when the indicator light or the app signals |
| Main brush | Clean every 2 weeks, replace every 6 to 12 months | Series specific; check the exact model's guide |
| Side brush | Clean monthly, replace every 3 to 6 months | Series specific; check the exact model's guide |
| Mop cloth | Clean after each use, replace every 3 to 6 months | Model specific |
The filter line alone explains why cross-brand price comparisons mislead. A Roborock washable filter is replaced once or twice a year. A Roomba filter is replaced about six times a year, and it cannot be washed to stretch the interval. Over three years that is roughly 3 filters against roughly 18, before any price per filter is even considered. A Black Friday discount of $50 in favour of the faster schedule brand can be consumed by its own maintenance rhythm, which is why the schedule belongs in the comparison and the suction figure, the number every banner leads with, decides almost nothing about cost.
Worked example: three years with a self-empty dock
The worked total below uses the Roborock Canada prices from the bill teardown and the Roborock manual intervals. Every assumption is labelled, so the calculation can be redone with different ones.
| Consumable | Assumption (labelled) | Three year cost |
|---|---|---|
| Dust bags | One bag lasts about two months in a home running the robot most days (assumption, using the roughly 60 day bag life Roomba publishes for its Clean Base as the guide); 6 bags a year, one 6 pack a year at $46.99 | $140.97 |
| Filters | Replaced every 12 months, the slow end of the manual's 6 to 12 month interval; one filter a year at about $24.00 from the $47.99 two pack | $72.00 |
| Side brushes | Replaced every 6 months, the slow end of the manual's 3 to 6 month interval; two a year at $24.99 | $149.94 |
| Total consumables, three years | Before tax; mops and cleaning solution excluded | $362.91 |
Added to the checked robot price, three year ownership of the example comes to $999.99 plus $362.91, which is $1,362.90 before tax, or about $121 a year in parts after the purchase year. Homes with pets or daily mopping will land above these figures, because the intervals shorten with use and mop parts are excluded here. Homes that stretch intervals toward the manual's slow ends land near them. Either way, the comparison rule holds: when two discounted models are within about $100 of each other on Black Friday, the maintenance schedule and the parts prices are likely to decide the cheaper ownership, not the sticker.
Verify the dock variant before you pay
The same base model is commonly sold in two forms, with and without an auto-empty dock, separated by a suffix in the model name. The dock version costs more and starts the bag bills. The plain version costs less and empties by hand. Neither is the wrong product, but paying dock money for a listing that ships without the dock, or comparing a dock bundle at one store against a bare robot at another, produces a fake saving in both directions. Verify with the manufacturer's own listing, in this order:
- Match the full model name, suffix included, between the sale listing and the manufacturer's product page. Treat any suffix difference as a different product until the pages prove otherwise.
- Confirm the dock in the box contents, named explicitly, not implied by a photograph of a dock beside the robot.
- Price that dock's bag on the manufacturer's store, using the bag table above as the pattern: the correct bag for the model family, in a multi pack, converted to a per bag price.
- Confirm the exit terms before the discount ends: on the checked Roborock Canada page, returns or replacement run 30 days from delivery and the new product warranty is 1 year, valid only in Canada. Other brands set their own terms, so read them on the listing being bought, not from memory.
When the cheaper robot costs more, and when it does not
Timing helps before arithmetic. Robot deals follow a pattern worth using: the models most likely to be discounted deeply are last year's flagships with a newer successor, while a model launched in the last few months is rarely cut hard. Settling on one exact model before the sale, with its parts priced, converts Black Friday from browsing into a single price check. Bundles need the same discipline. A bundle that includes spare bags, brushes or mop pads adds value only if those parts would have been bought anyway, at the prices in the teardown. Parts that would never have been bought are not savings, they are inventory.
The cheaper robot genuinely costs more when its filter and brush rhythm is faster and its parts are priced at the top of the range, and the three year gap quietly passes the sticker gap. The cheaper robot stays cheaper when its schedule is the slow one, its bags are the $5.48 per bag kind rather than the $7.83 kind, and the home's use is light enough that intervals stretch. There is no brand level shortcut here. There is a model level calculation, and it takes about ten minutes with a manual and a parts page.
First month checks that protect the deal
- Save the manual's maintenance table for the exact model, and set calendar reminders at the slow end of each interval as a first pass.
- Order the first bag and filter replacements before the included set runs out, priced from the manufacturer's store, so a stock gap never forces a full price emergency purchase.
- Register the warranty and save the receipt with the sale price recorded; the checked example carried a 1-year warranty, and the return window was 30 days from delivery.
- Watch the first bag. How fast it fills in this home replaces the two month assumption in the worked example with a measured figure, and the three year budget can be corrected while it still matters.
What success looks like: the robot bought on November 27 was chosen on its three year total, its first year of parts is already priced and calendared, and no part of the bill arrives as a surprise in January.