You'd probably expect to spend less than £20 on a reusable bottle. But the wacky world of the Internet of Things has bought us the Bellabeat Spring, an intelligent water bottle that costs up to four times that.
The Bellabeat Spring, which is available for £77 on the brand's website, is kitted out with sensors that track your water intake and send you hydration tips.
To see if the Bellabeat can genuinely help you live a healthier lifestyle, we handed it over to a panel of testers.
If you're thinking of adding a fancy reusable water bottle to your Christmas present list - for you or someone else - read our thoughts below and find out how the Spring measures up to rivals.
Of the 20 reusable water bottles we've put to the test and scored, the Bellabeat Spring is the most expensive by quite some margin.
The price is a little less surprising when you learn that it's packed with volume and movement sensors that track how much water you're drinking.
But tell somebody you've spent the best part of £80 on a reusable water bottle and the most likely response will be baffled amazement.
So what features can you expect from such a pricey container?
The Bellabeat Spring is a plastic water bottle that holds almost half a litre of liquid - 473ml to be precise. The bottle is free from Bisphenol-A (BPA), a chemical that's used in some reusable plastic and has been associated with potential health risks.
The Spring partners up with a smartphone app (compatible with iOS 9 and later or Android 4.3 and later) to help you monitor your water intake. The app also works with Bellabeat wellness trackers, including the (£93) and (£108).
Essentially, the Spring is a portable health coach that encourages you to drink more water by serving up personalised targets and reminders. It backs up your data to the cloud.
The Bellabeat Spring's brains are tucked into the base of the water bottle, so you'll have to unscrew that part before putting it into the dishwasher.
The brand doesn't recommend putting hot liquid in the bottle as it could cause the Spring to give inaccurate readings.
You don't need to spend nearly £80 this Christmas to help someone keep an eye on their water intake. Two other bottles we've tested cost just £10 apiece, and could be good secret Santa options for fitness buffs. Each has a less high-tech way of tracking water intake.
The Joseph Joseph bottle we've tested costs just £10 - it may not have its own app, but a small space on the lid reveals a new dot every time you fill the bottle up (up to four dots before it resets).
Meanwhile, the £10 Thermos Hydration Water Bottle has numbers drawn on to the lid, which you can twist to keep track of how much you've had to drink.
The Bellabeat Springs' super-smart features may still tickle your fancy and you may be able to get it cheaper in a sale (some online shops currently have it on offer for around £50). But is it any good as a simple drinking bottle?
We went hands-on in our test lab and asked a panel of users to rate the Spring on how easy it was to drink from, how comfortable it was to hold, and how easy it was to dismantle and clean.
Our expert reusable water bottle tests have uncovered five Best Buy models, all of which are well constructed and nice to use. One of our top picks is brilliantly suited to camping trips and is made from replaceable parts that you can buy on the brand's website.
But it's not all good news. Our hands-on time also uncovered a lousy reusable water bottle that scored less than 50%.
It ruined our water with an unpleasant plastic taste and the fiddly lid was a literal pain, with one of our testers getting a poke in the eye when trying to take a sip.