This is a theory I have which has not been put into practice yet, so I may get a few people to test it out...
If you have W-item and can use the cheat whereby you have an unlimited amount of any item in your inventory, could you not continue to replicate Magic, Speed, Power, Luck sources until you max out you stats?

Na i dont think so, coz they have to be used in the menu not during battle, i think. i woulda tryed it too, in fact i will attempt it.
dont think it will work thou.

It don't work, it just work for battle items.