Hello all I am at work and I do not have access but I have heard somewhere that if you do your enchant to a white item before upgrading it with the tempers/alloys etc, the upgrade actually increases the value of the enchant, however if you do the enchant after you have already done the temper/alloy upgrade its a fixed value in the tooltip and it does not get bigger.
Could anyone confirm this, if possible separately using woodworking, clothworking and blacksmithing?