Last Summer I bought a second generation Apple TV brand new for £100. Earlier in the year (I think it was March), Apple released a third generation Apple TV capable of 1080p playback, as opposed to the 720p that the 2nd generation offered.
If you still have a second generation Apple TV, my advice would be to sell it on eBay… and quick. I just sold mine for £182! Why? One simple reason. The second generation can be jailbroken and the third generation can’t (yet). There are quite a few Apple TV’s for sale on eBay at the moment, but more than enough people willing to buy them. My advice is start with a 99p start price to attract bidders and have a 7-10 day auction. There aren’t many items you can sell that are a year old and it earns you £82 profit!