Theoretical the level of the item is the one that determines the amount of fame you recieve the most.
For example Gold sand will give you more rep than Gold ingot.
The money however, does depend on the kind of workskill, so Gold ingot will give you more money than Gold sand.

Supposedly the amount of fame and money also depends on the person you are selling to (warehouse/kingdom buyer). To prove which theories are correct, we need a lot of examples.