I trust the dep services to do my YJ bidding for 
me, but for Ebay, I usually put in a placeholder 
bid right off the bat just to say, "Hey, I'm 
interested in this cel." There's a small group of 
people who will respect that "dibs", and I 
respect their "dibs" in return, and we chitchat 
about which ones we're going to pursue seriously 
and which ones are up for grabs if one of us is 
outbid by a third party. If I do get outbid by 
someone, I'll usually come back and snipe with my 
maximum in the last 15-20 seconds of the auction 
if possible. If I can't be around for the 
auction's end, I'll try to bid my absolute 
maximum the day it ends.

Fortunately for my bank account, though, Ebay's 
been rather slim pickings for my concentration-of-
choice, though YJ has been excellent recently. :o)