Ours used to work nicely like that until they changed increments from 17p,17p,17p etc. to 18p,19p,18p,19p.

If I have to send a packet with 3 to 8 chips in it overseas I would have to use 5 stamps minimum to make the value.

Do you stamp most of yours yourself and thus avoid queuing up? Ive heard different stories from different people in the US. Some seem to have to go to the post office whether they stamped it themselves or not.