Product image supplied by the brand
In this guide
Three products share a structure that price tags hide: a one-time object attached to a recurring line. An £84.99 tracker whose coaching sits behind £7.99 a month. A £59.99 toothbrush handle whose head Philips says to replace every three months, a four-pack of which Amazon.co.uk sells at £19.99. A £31.00 cat fountain whose filter pad Catit says to change every 30 days.
The purchase price is the smaller decision in two of the three. For the tracker and the fountain the makers print every number you need, so the yearly line is arithmetic rather than guesswork; for the toothbrush the handle's own page is silent on heads, so the price comes from a retailer's listing. Do the sum before the first purchase rather than after the first renewal.
The things in this guide
A closer look at the products, who they may suit, and what to check before buying.
Fitbit Inspire 3
Google Store UK lists the Fitbit Inspire 3 at £84.99, and Google Health Premium renews at £7.99 a month, which is £95.88 a year, £10.89 more than the tracker itself.
Before you buy: The plan is optional. Google's Premium page lists activity, sleep, health-metric and alert features under a Google Health app column and coaching under Premium, without saying which of them the Inspire 3 supports. Decide what you want from the coaching before treating the subscription as part of the price.
Price checked 17 October 2026. Retailer prices can change.
1100 Series Sonic Toothbrush · HX3641/02
The Sonicare 1100 handle is £59.99 at Philips UK, and the manual says to replace the head every three months, four a year. Philips UK's handle page shows no head, but Amazon.co.uk sells a four-pack of ProResults heads at £19.99, which is one year of heads, about a third of the handle's price.
Before you buy: Compatibility rests on the Amazon listing, which says the head fits every Sonicare handle except Philips One; Philips UK's own six-pack page does not name the 1100, so confirm the fit before you buy.
Price checked 17 October 2026. Retailer prices can change.
Flower Fountain
Catit UK sells the Flower Fountain at £31.00 and pads at £15.80 for six. Twelve pads a year is £31.60, slightly more than the fountain, before the time to strip the pump every other week.
Before you buy: Pads in 2-packs cost £7.20 each pack, £43.20 for the year. Several cats using one fountain may need changes sooner than every 30 days, according to Catit.
Price checked 17 October 2026. Retailer prices can change.Every price tag with a consumable has a second line
Google lists the Inspire 3 at £84.99 and Premium at £7.99 a month, which is £95.88 over twelve months. Philips lists the Sonicare 1100 at £59.99 and tells owners to replace the head every three months, four a year. Catit lists the fountain at £31.00 and tells owners to change the pad every 30 days, twelve a year. Each is a one-time price with a recurring line underneath, and the recurring line is the maker's own instruction, not an accessory upsell. The toothbrush's head price comes from Amazon.co.uk, since the handle's page does not give one.
The habit that protects a budget is writing the second line before buying, in the same currency as the first. Multiply the unit price by the number of times a year the maker says to buy it, then set the total beside the object. By that arithmetic, the plan and the pads each cost more than the thing they serve inside a year. The toothbrush is the exception: a year of four heads is one £19.99 pack, about a third of the handle.
The tracker: a plan that costs more than the wristband
At £7.99 a month, Google Health Premium runs £95.88 across a year, against an £84.99 device, so a person who keeps the plan spends more on software than on hardware before the first anniversary. Google's UK Premium page describes the plan as personalised coaching built with Gemini for fitness, sleep and wellbeing, and states that the coaching requires the subscription, sold separately.
The decision is not whether the plan is good but whether you want what it adds. The Inspire 3 page lists its own features, including Connected GPS that borrows your phone's GPS for pace and distance, and a 5 ATM water rating; the Premium page sets a Google Health app column (activity and sleep tracking, health metrics such as heart rate, HRV, breathing rate, skin temperature and SpO2, and health alerts) against Premium, which it describes as all Google Health features plus a personal health coach. That list is written for Pixel Watch and Fitbit devices in general and does not say which items the Inspire 3 supports. Someone who wants coaching should budget the £95.88 as part of the tracker's real price. Someone who wants a wristband that counts and buzzes can stop at £84.99, and the plan can be left alone.
The toothbrush: heads priced outside the handle's page
The Philips UK page for the 1100 shows £59.99, a 14-day battery claim and a UK 2-pin power adapter among its accessories. Its Parts & Accessories list shows the adapter and a charging base and no brush head, so there is no head price on the page a buyer lands on. The user manual says to replace the head every three months, which makes four heads a year.
Philips UK's own six-pack, HX6016/87, is a poor guide: its compatible-handle list names ProtectiveClean, ExpertClean and Series 7900 handles and not the 1100, which ships with a SimplyClean head, and its price did not show on a later read, so it is not used. Amazon.co.uk, shipped and sold by Amazon, lists the ProResults four-pack, HX6014/87, at £19.99 and says it fits every Sonicare handle except Philips One. That is Amazon's wording rather than Philips's, so confirm the fit before buying. Four heads a year is one pack, £19.99, about a third of the handle. The manual also says the wall adapter is not included, so budget for a USB plug if you lack one.
The fountain: a monthly pad and a biweekly teardown
Catit tells owners to replace the Flower Fountain's pad every 30 days or when it looks saturated, and notes that multiple pets may need changes sooner. Catit UK sells pads in twos at £7.20 and sixes at £15.80, so twelve pads cost £31.60 as two six-packs or £43.20 as six two-packs, against a £31.00 fountain. The fountain and one six-pack together come to £46.80, which clears the £40 free-delivery threshold on the same page.
Labour belongs on the second line even though it never appears on a card statement. Catit's cleaning guide says the pump should be disassembled for cleaning on a biweekly basis; read as every two weeks, that is twenty-six teardowns a year. A fountain kept to that schedule is a monthly purchase and a biweekly task, and a fountain that is not is a bowl of standing water with a pump in it. A household choosing between this and a bowl rinsed daily is choosing between two routines, and the money is the smaller half of the choice.
When the second line should end the conversation
Skip any product whose recurring line you cannot compute before buying. A subscription with no annual figure, a consumable with no price you can find, or a maintenance schedule the household will not keep are all reasons to stop rather than to hope. The purchase price is the easy number; the one that matters is the one you have to go looking for.
And skip the arithmetic entirely when the recurring line is optional and you know you will not opt in. A tracker used without the plan is an £84.99 purchase and nothing more, and treating it as a £180.87 first year is as misleading as ignoring the plan would be for someone who keeps it. Write the second line honestly for the way you will actually use the thing, then decide.
How we put this together
Built from the product pages and listings below, without test scores or results we have not measured. Specifications and prices change, so check the original page for the exact model, current price, delivery, and returns.
- Google Store UK: Fitbit Inspire 3 (opens in a new tab)
- Google Store UK: Google Health Premium (opens in a new tab)
- Philips UK: 1100 Series Sonic electric toothbrush HX3641/02 (opens in a new tab)
- Philips UK: Sonicare ProResults 6-pack brush heads HX6016/87 (opens in a new tab)
- Philips Sonicare 1100 Series user manual (opens in a new tab)
- Catit UK: Flower Fountain (opens in a new tab)
- Catit UK: Flower Fountain Replacement Filters (opens in a new tab)
- Catit: Flower Fountain Cleaning Guide (opens in a new tab)
- Amazon.co.uk: Philips Sonicare ProResults 4-pack brush heads HX6014/87 (opens in a new tab)
