We are trying to get the most accurate prices on the site by analysing the Steam Market. We have scripts doing mathematics to calculate the prices of your items, it depends on if it is a knife, a single skin for a weapon, a sticker, or a key.
Calculation example: Let's say that you have a knife. The Steam market price of that knife is estimated to $50 and we are giving you 90% of the market price. The mathematics part is going to look like this: