I have been successful in play despite feeling a bit of the empty pockets disease. There are many options in the game, but early on I feel that there is a real need for +3 weapons, and soon there becomes a need for +4 weapons. On top of that, other things that you may want to buy include potions, scrolls for spell books as well as specific battle encounters, wands, rod of resurrection, other vanilla game store items and Cromwell upgrades, and the new Sikret upgrades from Cromwell. What purchases do you feel are the best value before the underdark, after the underdark, and in ToB?

I think a good general rule with money managment in IA and one I stick to my self is never spend money on something that you wont be using by TOB. This means save your money for buying upgrades, upgrade components and very high end kit only. It can be quite tough but will ensure you can afford all the upgrades you want in late game. Meanwhile it is more than possible to survive with the kit and potions you find around the game.

So far I"ve bought quite a few things actually and right now I'm in the Underdark and have about 100,000 gp. I can't wait to get back to Cromwell and blow it like a kid in a candy store.

Hope you are not running with a Wild Mage

It would be funny and annoying for it all to go poof in a wild surge