I've been following, and bidding on, a greenhouse on eBay. 8ft x 6ft. It was local which was a big plus but still needed complete dismantling (& reassembly of course).
It went for £123 which was more than I was prepared to pay. Rule of thumb is something like - if a new one (Homebase or B&Q) costs £250 I'm not prepared to pay half that if I have to dismantle it, transport it and reassemble it. Doesn't seem like much of a bargain after all that!
But I'm watching five more.