Disagree.  The purpose of giving payment details/proof of identity at an Auction house is to dissuade bidders from bidding, winning, and not paying.  Whether the item is bought with the intent to sell or whether item is kept or purchased for someone else is not really relevant because the fact is, the bidder entered a bid, won the auction which is seen as a contract, and should pay.

If bidders don't pay (excluding legitimate reasons) then they should be held accountable. 

And I also disagree with the 'buyer didn't lose any money on it because they can just relist the item' argument.  

My time is worth something.  And I have had the experience once of having 'sold' an iphone for hundreds of dollars, but buyer didn't pay because they only bid 'just wanted to see what would happen/boyfriend bid accidentally/ changed their mind blah blah'.  Second chance bidders had moved on by the time dispute had been opened and closed, on relisting, the demand for the item had then waned to the effect that I made a loss rather than the profit I would have made if the bidder had 1) not bid or 2) paid. 

So yes.  I lost money because a bidder didn't pay.  Depreciation and auction timing do come into play with the sellability of some items. 

And I think there should be higher penalties.  I like the idea of 'three strikes you're out' (for a certain timeframe).  And while I'm thinking about it, I also think there should be a limit to bid retractions.  (Or is there one already and have I missed something?)  But perhaps that last one's best for the 'bid retraction' thread . . . .