Timeboxer
Explorer
Is this normal practice? I've been gone from the game for some time and I'm relearning but I always remembered the DMs letting you use your gold as you wanted to - as long as it was legally acquired.
As I said to someone the other day: "It's probably possible to do it, but it's probably a bad idea to do it."
Theoretically, the DM can restrict whatever he wants -- it's his game. But practically speaking, he probably shouldn't. It reduces the investment you feel in character customization, and, to be honest, any gold that I can get my players to spend on non-combat items is gold I want them to spend.
(Actually the ideal situation for a DM is to give your players an amazingly powerful item that they are too afraid to use and want to get rid of. But I digress.)