I can see both sides of the argument here, but at the end of the day I would not put my money into something I was unsure of, and the fact he was so quick to offer a cancellation of the sale shows to me that there is more to it than meets the eye. It may be a simple case of the auction not making as much money as he had hoped, so he will be an arse to try and stop you buying it so that he can relist it and try and make more money on it.

I have sold/bought things off ebay (not a huge amount but more than Karl) and not once have I had a problem collecting items from peoples houses, meeting at random places, or people collecting things from myself.

At the end of the day it's a lot less work on my part if someone comes and collects the item!

Take his offer and walk away!