Keigo and Makoto handle it very fairly. Utmost 
priority is given to those who contact them 
first..even if someone who is a regular gets to 
them later and is willing to bid more. They also 
will not divulge what the later request was 
willing to pay, so that if the second person 
finds another Deputy Service, they do not need to 
be worried that Celga will pass this information 
onto the first person. 

If the auction goes higher than what the original 
person was willing to pay, they contact the next 
person in line.

If for some reason they receive two requests 
simultaneously (I'm sure this happens very rarely)
priority is given to the person who has done 
business with them in the past. 

They explain this pretty thoroughly on their 
site. I suggest taking a look. ^_^

-Megan