I've bought phones and such off of ebay for >£200, with no problems.

The best piece of advice I could give you is, be precautious.
Check out as much about the seller as you can, before buying the item - Look what they've been selling, buying, feedback, etc.

It may be a good idea to email the seller beforehand if you have any suspicions about the item. It'll also give you a good idea of their attitude, incase you do get any problems with the item.