Seeing all of this comments for pet peeves/common 
courtesies, etc...  I have to ask:  Many people 
do not mind receiving offers on their cels, 
others clearly state that they'll never sell at 
any price.  I was wondering, for those that don't 
state at all whether they will/won't take offers 
on their cels....say you saw a cel in their 
collection that you'd die for...would you make 
them an offer?  I'd fear that since they didn't 
mention offers, it would anger them to receive 
one, but I'm not sure.  Would it bug you?