When I bought the Bird From Barry, I wired the money directly to his account. No problem. No way I could have reclaimed it afterwards.
Money order, no problem. If you get it, it means that I have paid.
Western Union will not issue it unless they have the money from me.
PayPal: when you´ve got it you´ve got it. No way to reclaim.
PayPal will not send you the money unless they have got mine.

I think if it shows up as available funds it has cleared. Otherwise no bank would let you withdraw it.

Just give them the total, with freight and all, and wait for the check to clear. Any serious buyer will accept that.