I have to disagree- I think if you really want to 
give someone "dibs" you should be up front about 
the price.  Decide you much you want for the cel, 
and if they can pay it, they get it.  Don't tell 
someone they have dibs, then keep accepting 
offers.  My thought is you offer it to that 
person first, and if he or she doesn't get back 
to you or doesn't have the money, THEN offer it 
for general sale.  I believe it's wrong to dangle 
it before someone and then snatch it away at the 
last minute.