Hi,
We've bought most of our coins from Oakcoins (
www.oakcoins.com). Join up to their mailing list and you'll get sent free postage from time to time which makes it ace.
Clearly, make sure you keep it under £18 to avoid customs charges.
A couple of friends of ours run Geotees so we use them quite a lot. I've often found it's just as cheap to get official geocaching.com merchandise from the US too. Hobbycache used to be great for this, but they've let their site go
