Aha, you caught me only part-way on this one Steve, since now you have to un-do the price averaging if you are to consider sold and unsold separately. To make myself clear, let us take two items, both originally listed at $4, one sold at $20, the other remained unsold at $4. With my approach, the average price is $12, and the total fees are: 2*(0.0525*12+0.35) = 1.96 . Taken separately, the fees are: 2*.035 +.0525*20 = 1.75 and the relative difference gets smaller as the sold item's value increases. You are correct, however in that I should refine my arithmetic. Thank you.