Never below ~£60 at Amazon, not too bad a price for a fairly simple waterproof tracker/watch. Battery supposedly lasts a year too.

Blurb:

Get up, get moving and monitor your daily activity in style with the Garmin vívofit® 2 fitness activity tracker. The display is always on so you won’t miss a beat. Turn on the back light to see your stats, even in the dark.
Intelligent, Personalised Fitness Stats

No matter how you live, make every step count with Garmin vívofit® 2 fitness activity tracker. It counts your steps, calories and distance throughout the day and tells the time of day. vívofit® 2 learns your activity level then assigns an attainable personal daily goal. As you meet your milestones, vívofit® 2 adjusts your goal for the next day, gradually nudging you toward a more active lifestyle. It also monitors total sleep and periods of movement or restful sleep.

Audio and Visual Motivational Activity Alerts
The move bar with audible alert reminds you to stay active throughout the day by displaying a red move bar and sounding an alert after one hour of inactivity. Additional segments light up for every 15 minutes of inactivity. Just walk for a couple of minutes to reset.

Exceptional Battery Stamina and Waterproof Technology
Garmin vívofit® 2 stays on for more than a year without having to change the battery, so you don’t have to worry about recharging. It is water-resistant to 5 ATM, so you can shower or get caught in the rain, worry free.

Heart-rate Monitor Compatible
With a daily step goal, heart rate monitor (sold separately) and activity timer you’ll be motivated to walk further, do more and be fitter than you ever imagined.

Wireless Syncing
Garmin vívofit® 2 automatically syncs to Garmin Connect™ with paired mobile devices as strategic times throughout the day, such as when a goal is met or when several steps have been taken since the last sync, to make it easier than ever for you to plan, review and share your progress. Join the movement today and take those first steps towards a bright direction.
Personalised Band Colours

Show your true colours – Garmin vívofit® 2 comes with 2 band sizes of the same colour. Additional bands are available as accessories, in an exciting range of fashionable colours.

Battery Life Over 1 year
Brand Garmin
Display Size 25.5 x 10mm
Weight 25.5g