IMO, the minor increases in omega 3 and CLA don't warrant a 200% increase in price. Grassfed meat is incredibly overrated IMO. Unless you have storage to buy your own cow - which is a fantastic idea IMO - I wouldn't buy it. Buying individual cuts of grassfed meat is a great way to go broke, and the online retailers are incredibly overpriced when you factor in shipping and packing costs. I'd rather have grain fed meat and eat a pound or two of salmon per week to balance it out. That way I get beef AND salmon for less money than just marginally better beef
If you can afford it, go for it. If you have storage space, go for it. IMO it's the least important Primal principle, and should be undertaken last. Remember, grain fed is a luxury item in many countries due to the improved texture.
Don't put your trust in anyone on this forum, including me. You are the key to your own success.