I've been after this for a while for using my GoPro whilst Scuba diving, and I've just had the CamelCamelCamel alert alerting me to a price drop. According to CCC, this is the cheapest it's ever been at Amazon, and I'll be ordering accordingly.
Wanted to share in case it's useful to anyone else. I'd done quite a lot of research into various flotation devices previously and decided that this was the best for my purposes. If anyone else has any other suggestions, please feel free to share!
FYI - most other stores that I can see are selling for between £22.50 and £23.50 - in addition, some of these being sold are the previous version that do not include the carabiner or wrist strap.
Hope this helps!