$50 is pretty pricey for a protein powder. Lemme guess, GNC?
If you're going to eat meat as a protein source, stick to your poultry. It's leaner and easier to metabolize.
With red meat, you're getting a lot of fat (which admittedly you need in some amount, but for the amount of protein you want to get out of it, it's not worth it), and because of the connective tissues in red meat, it's more difficult to break down and digest.
With white meat, you have a low fat, low cost, extremely rich protein source that, for my taste, is much more versatile in meals.
The "other white meat", pork, isn't so bad as long as you stick to ultra-lean ham. Some porks (stay away from most sausages!) can be killers in terms of saturated fats.