WBL in my opinion does not award good roleplaying and good roll-playing.
Wealth by level is a game balance guideline. It the tool by which authors/GMs can estimate some of the variable power of the party. If you have 10x WBL, then what challenges a 1x WBL party will probably be significantly easier for you. If your GM is customizing encounters based on the actual play of whats going on at the table, than by all means throw wealth by level out the window.
Fabricating instant wealth doesn't strike me as particularly good roleplaying either, irregardless of how much weight/size mathematics and the detailed compilation of what raw materials are consumed. Unless there is a lot more going on not mentioned, this looks like a hand my GM a printed list, and ask for the appropriate amount of coins in return.