No, there is no sanction on buyers because in law a contract only exists between buyer and seller AFTER money has changed hands.
All this stuff about entering a contract when you make a bid is just e-bay spouting bollocks.
Business e-bay sellers offering goods for sale at a fixed price are supposed to abide by the 'Distance Selling Regulations 2000' if the item is sold for a fixed price on a 'buy it now' basis. The regulations give you 7 days after receiving any goods purchased to cancel the purchase and demand a...