I don't like that either, but it's this dealer's 
right to do this. AndHe just takes advantage of 
the fact that people who bid on ebay, YJ or 
whatever, bid several times by adding each time 
very small increments of $, instead of bidding 
their real max price from the start. If your max 
bid was $100 more than the actual price 1 minute 
before the auction ends, then if this seller bid 
at the last second he would be "taken into his 
own trap" because he would fail and wouldn't 
outbid you.

In conclusion, it's you to stop playing while 
participating to an auction. You know that when 
this dealer re-sells this item a few weeks later 
its price will be much more expensive, so bid 
enough money from the start and you won't be 
outbid anymore...