OP, I've spotted your auction is far under the Bitcoin price at present so I assume you're not going to accept anything less than face value?

If it does sell for less, which is very unlikely in the current climate but you never know, then you may as well tell the winner to sod off and peel it and sell the Bitcoin and alts off it which will be far less hassle and more secure for you, or offer it up here instead to rescue it.

If it were me I'd only do the sale meeting in a bank and accepting cash or bank transfer straight from them to you. And once again balls to Paypal and triply even more so if a deal is done in person.