...To cheap cels

Neither is being poor/sick/lame/brainimpaired

To be fair I've only had this experience a couple 
of times and it is a pathetic attempt at talking 
down the cel price... Pathetic because it is 
obvious.

Annoying as it may seem - I still think that a 
polite answer doesn't hurt. It may be just a 
clash of cultures in terms of bargaining tactics. 
Many cel collectors live in different countries 
and there are different methodologies of making 
offers/negotiating etc.

The only time I've had to take time off before 
replying was a high handed email from someone 
which was a terse: 
"You will sell me this cel for $X - pack it up 
and ship it to such and such" ($X was a 20% of 
what I had paid).
I struggled to control my temper replying to that 
one.