I just completed 50 auctions of individual chips. All 50 sold. I put in my description "1st chip is $2.50 and each additional chip is 0.50. I know my shipping is less than what I charge, but it gives me the option to add a surprise chip or extra S&H discount for special customers. I have 100% rating so I'm doing something right.
Out of the 50 auctions there were only 14 winners. Only one with a single chip. I used the ebay shipping label, but I print it on special self sticking label paper that can print two labels on an 8 1/2 X 11 sheet. ( buy at Office depot or Office Max ). It is a lot easier than cutting and taping to your bubble mailer.
You need to consider all costs in your S&H, postage is only one.