In my opinion this won't be fair until you add something about the complexity of the item. The DC to craft a 40 gp plain padlock must be higher than the DC of a 40 gp silver spoon. In my group, the player and me (DM) usually decide the DC together - both trying to be as impartial as possible :)...
I was wondering if this was a joke too. I don't really understand the need for this - unit conversion isn't really that hard. Getting it explained from Skip Williams is like having Bill Gates explain how to use the calculator in Windows ;)
I'm not really looking forward to part II and II :\...