First of all, this website may be helpful to find specific items and their original cost (not in trochus):
https://item.era-go.com

Second, this also is a guide of items and their price in trochus (Im not sure if this is exactly what youre looking for but I think it is):
http://www.graalians.com/forums/showthread.php?t=19256

There was a really good guide I found a while ago but I can't seem to find it