I've only use deputies twice, Celga once and Sato 
once.

Well, I myself prefer Sa
to...not only is he super-nice, but I find 
he's the cheapest for small auctions. His fee is 
20 percent of what you bought, and his minimum 
fee is 1,000 yen, which at the current rate is 
cheaper than Celga's 10 dollar minimum. He's best 
for small auctions because of this...you don't 
have to wrry about the fact that you're paying a 
fee of 10 bucks to bid on a 2,000 yen item.

However, HobbyShopK 
can turn out to be cheaper, ($6 per bid, plus 10 
percent of the final bid price) depending on what 
you're bidding on. 

Really, what you have to do is look at what 
you're bidding on and figure out the general fees 
for each (the bank tranfer fees and shipping tend 
to be the same, so just work out the main fee), 
and use whichever is cheaper.

Celga has great service, not knocking that. Just 
poiting out alternatives.

-Misha