If you didn't want to avoid auctions all 
together, you could always try the Animanga 
auction. 

IMO, silent auctions seem to be a pain in the 
arse for all parties envolved.  One-bid offers 
could make that easier, but sometimes if you 
want a cel bad enough, you are willing to outbid 
others. (plus it can be scary to make one HUGE 
bid when it may not even have to be that 
high....and you don't know what you would be up 
against..)

Or you could do a semi-silent auction where you 
post the high running price on your site...

I guess you have a lot of options.  ^_^