Personally, I buy protein powder even though I know the ingredients are actually too cheap to justify the price. But I’m too lazy, and the reward of a cold chocolate shake after working out makes me forget about the outrageous cost. It’s a little guilty pleasure I’ve come to terms with.
Mostly convenient sources of protein such as Brust drinks, Leanfit powder, Simple Protein Bars, and Okios Pro Yogurt. Food is often cheaper, but also higher in calories, sugar, and salt.