I have a zip lock bagful of the TAGS that work with the Golf Pad score and shot tracking app for a smartphone. If you buy them from Amazon or directly from golfpadgps.com, they're $99 for a set of 15, or 3 for $20. I have 19 of them in total, and one is modified to fit in a Super Stroke putter grip and another is screwed into a wine cork through a piece of leather kinda like a key fob.
These are all just one season old and work great. I've switched to using a smart watch instead, so I'm trying to sell these.
(I'm a fan of the app, I think it's the best choice available especially for the price. I'm a stat nerd and it has been a huge help for me and my game.)
I have these listed on CL & FBMP for $75, but I'll take $60 plus postage, which should be minimal.