Multi-vitamin, fish oil, and creatine are all great as far as bang for your buck. I don't think protein powder is as important as people make it out to be, IF you are getting plenty of dietary protein.
There are other ways to get what you want cheaply. Bulk powders are great. You can get bulk BCAA powders, then mix them with some sort of flavoring like crystal light or maybe gatorade if you want some carbs to go with it.
Current PRs at 242, raw w/ wraps- 525, 355, 605, 1485
Roboro tui, perimo vester adversarius
(Build yourself, destroy your enemy)