I think offering free shipping on common chips will hurt your sales. The shipping discount is key as it drives the average price per chip down, and heavily incentivices bidding on multiple chips. As a buyer - I will never bid on or offer to purchase a single chip - it is always too expensive. To include shipping on a common chip you would have to start your auction off at $3+ to make sense - which is my bottom price of a chip I offer at .99 cents with $2.50 shipping. With the lower price - I may get a buyer to bid on 3, 4, 5 or more chips - which they would never do if each was $3.

As an aside - shipping is SHIPPING AND HANDLING - I dont have any issue with charging $2.50 when my pure cost is .65 to .70 cents for a single chip.