How long is reasonable to wait for buyer to collect?

[clam]

Auction for storage shelving/cupboard units ended last Sunday evening. Buyer paid immediately. Emailed me to say he would let me know when van available to collect.
Have heard nothing since (and have emailed him to ask) but my new furniture is due to arrive this week and it will be very awkward to store this stuff for much longer.
What should I do?

i would e-mail him and say that he needs to collect by x date otherwise you will have to refund him.

had you told him, or stated in the auction, that it needed to be collected by a certain date?

No, other than to state that we were selling due to a refurb. Was slightly when I realised he lives in Scotland and I'm in the SouthEast, but his initial email implied that he has access to vans doing the trip.

You need to refund his payment anyway - you should only accept cash for collection items, never take paypal for them.

Aside from that I would probably wait a week to be honest, unless they have agreed with you otherwise.

Less than 5 minutes after the auction ended, a message flashed up that he'd paid. Why should you only accept cash? I'd have preferred that, actually, and it is what happened with the other items I sold.
Can you tell I'm new to all this?

If you accept paypal you need proof of delivery if there is a dispute - if buyer collects you obviously have no proof, so in theory they could pay by paypal, collect then initiate a chargeback and keep your goods for free.

If you log into paypal, click on the payment then scroll down and hit refund you can include a note there saying you require cash on collection and ask them when that will be

Your paypal account does need to be in credit for the full amount to do the refund so if you have spent it or transferred it to your bank, you will need to transfer funds back to paypal which takes a few days.

Assuming he ever turns up (and why would someone pay and then not?) then could I not ask him to sign a receipt?

no - you need online trackable proof of delivery like recorded, special delivery or courier