BLOCKED BIDDERS LIST. https://www.ebay.co.uk/bmgt/BuyerBlock?
Ebay do suggest the buyer pays and you refund overpaid postage, but it would not avoid the 75p charge for each item item.
After 4 days you can cancel sales for non payment, which gives non payer unpaid strikes, but more important they cannot leave you any feedback.
Cancelling for any other reason is just inviting negative feedback.