I will admit right off to never having been on 
the selling end of a cel transaction, so maybe my 
views are a little one sided. 

When I read "offers", the amount I offer is the 
result of balancing what I feel is a fair price 
for the cel and what I can afford. If its not the 
highest offer then that's OK. That's the nature 
of offers. When  I bid on a auction I start low 
with the understanding that it will go higher and 
I will have multiple opportunities to raise my 
bid. The initial bid I make on a acution is 
usually lower than the amount I can, or am 
willing, to pay. I expect that initial bid to 
fail. I plan on making other bids later, 
depending on how the auction progresses.

I don't particularly care if a seller runs an 
auction or takes offers, but whichever they 
decide to do will influence how I approach the 
sale right from the start. An opennig bid by its 
very nature is going to be lower than an offer. 
To say "I'm taking offers" then run the sale like 
an auction is to change the rules halfway through 
the game. It treats "offers" as opening bids. 

IMHO, the only time that taking a counteroffer in 
a "taking offers" sale would be approriate, would 
be in cases where the two top offers were the 
same or VERY close (say less than 10% apart). If 
the seller does not prefer one buyer over the 
other, then giving the two top collectors the one 
time chance to adjust their offers may be 
reasonable.

Sorry if this offends anyone, its just my slant 
on the situation. I realize there are many of you 
who may feel very differently about this. :)