Having used celga, I think the reason the bids 
seem so high is that:

1) you have to decide way in advance (like when 
the cel first comes up) what you want to bid so 
you make sure they are bidding for you.
2) you have to make sure you bid high enough that 
you aren't going to lose out to someone else thru 
Celga or another service
3) if you are the second bidder in line with 
CELGA, your bid from necessity is fairly high.
4) I personally have used CELGA when it was a 
matter of get the cel or die trying--I will put 
a "nuke bid" in with them to make sure I get it.

I don't think a deputy service is intimidating 
either way--it just depends how much someone 
wants the cel.  If you want a cel badly enough to 
use a bidding service, it's probably something 
that will go for a nice chunk of change.

(I don't know if any of that made sense--I'm very 
tired...)