Whenever you're buying cheap protein, make sure you check ingredients and make sure you're getting Whey isolates/hydrolysates..
but, i'm with ya, broke and in college. i try and keep these in my house at all times
whey&casein proteins (you could get all your protein req's from food, but it's honestly cheaper to buy the protein powders)
there are all kinds of discounts sites with brand-name products at rock bottom prices, out of respect for the site, i'll leave it up to you to find them.