I've seen it go on eBay for a bit in the past, can't remember exactly how much though. In fact, I can see some on there at the moment, but they are in early days:
http://search.ebay.co.uk/...pageZ50QQsosortpropertyZ1And btw, I personally find Gamestation a bit of a rip off when it comes to retro stuff anyhow, for instance in Portsmouth the other day, I saw a NES (unboxed) with Mario Bros (unboxed), can't remember how many pads but the markup was £35.