Because I don't want to predict how much an item will be worth based on trends. What I want to do is tell exactly how much an item is worth. The minimum amount that it will be probable to sell at, and the maximum. It's just math and it all depends on how often the players buy from the market. Correct me if I'm wrong but trends would only find what items are being bought more, which is useful. This method is "predicting" based on facts. This item has been bought for this amount. It tells you around the lowest you should buy or sell an item.

An example with the data Fish gave me (this is a small amount of data mind you, and I will be using the full data given to work out some better numbers when I have time): the market would tell you that currently a Supernova Force should be sold from 10811tc - 18975tc and that the majority of users have purchased Supernova Force at around 13432tc. Though for everyone's sake, if this is implemented I'd just round up to the nearest hundredth probably. Plus, with new data the rates would change based on the economy so to speak, so if people begin selling the item for lower universally, the approximation that the market tells you will change

I hope I'm not being confusing it's really late as I'm typing this D8