Psi, I buy Eas simply whey from dpsnutrition.com, it's about 25 bucks for a bunch of servings. Dieting is more expensive than Bulking for me...weird I know.
You can still do it , just lower the amount of protein, for example, eat 40 grams , 2 x a day, instead of 60 grams, 3 x a day. That should cut costs a lot.
Do a search, you might find a person or a company who is willing to take cash. Look through the back of muscle magazines, a lot of the owners of the companies that advertise don't really give a fuck. And remember to bargain and say "remember I'm paying straight cash".
Most will hook it up.