Actually this topic was brought up a few months back by none other then myself. I had all the equations, weighted for time (assuming that a merchant here longer had a better known name, not always the case). The one piece missing was the numbers. This is where it got sticky. If you went on a item by item basis then you essentially got to know what each merchant was making, not a good thing. If you went by catagory, you lost the aspect of a well known name being able to charge more. The numbers got skewed. If you went by catagory, price and number sold, you could get close or extremly far off. It basically came down to rosity stating that the numbers would never be published and I support that. Without the number, the analysis would never be done. Try the alternative, which actually works a little bit better. Browse the hot selling items for a while. Pick out your top selling item in dollars and see where it falls in the hot list. THis might take you some time to find it. Now once you have it located, take a look at the pages right before and after your item. Note the ones that would seem to fall into the same catagory. Take a note of thier prices. If the ones higher then yours are priced lower, they may be a key issue. If they are made by well known people that is another. Once you see these relations you can make a more informed decision on pricing. Granted this only works once you have a few items out there and they are actually selling.