I'm not big on paying the price for heavily advertised products -- especially for something like protein. The inexpensive proteins work just as well as Nitro Tek or EAS. You have to take into account that these companies are using
pro bodybuilders who use mass quantities of growth enhancing drugs to push their supplements and then saying that their product is responsible for their outrageous physiques. Save your money and buy an off brand until you can find research that proves one product superior to another. Ultimate protein is my favorite brand of protein because it is inexpensive because it isn't heavily advertised, and it works.
However, certain products are worth the extra money. Syntrax Guggelsterones are a good example. They cost more than an off brand, but when you break open a capsule it smells and looks like coffee, whereas most brands contain a yellowish powder. This reflects the extraction process and the inexpensive way to extract the product leaves it a yellow, much weaker powder. Take your time and look around the web for genuine info, not ads, before you make your purchasing decisions.