It IS dropping. More and more of them are being found, so they are becomming more available. Supply for them is going up. They are not as hard to find anymore, so i'm sure people will start seling them cheaper then the guy next door, just to get a deal. Eventually, shitloads of people will have an soj or more, and the demand will go down and down and down, until all sojs can get you is a fal rune or something.

Its the d2 economy.