I have no problem with auto-extending IF it works 
like that at a live auction - as long as someone 
is bidding, the auction stays active.  But I've 
NEVER been at a live auction (and I've been to 
many antique auctions, and conducted art and 
plant auctions at conventions) where the auction 
would stay open another 5 minutes or 10 minutes 
after the last bid.  The extension is usually 
around a minute, never more than 2 (or the 
auctioneer would be beating himself into a 
frenzy).