Rick, As David says, it all depends on the value of the chips. But no matter as the important thing is that you are not trying to rip off the buyer. This is the actual cost and you are just transferring it onto the buyer. No matter what you decide, it is fair (in my opinion.)

You see, to me it is the principle of the whole thing. It would not bother me whatsoever if a wanted chip cost me $1.50 and you sent it priority mail for an additional $3.50. But if you try to charge me in excess of $1.00 to mail a chips which cost $0.45¢ to mail, you sure won't hear the end of it for some time to come and I won't forget. You see, sometime in the future, it is most likely that you will want something from me and then I will take my revenge--many time over.