I haven't seen this answered in the forums so I figured I'd ask. Is there a difference between the brands of whey? Is more expensive whey better than less expensive? For instance: MuscleTech compared to GNC's brand. I used to pay $50-100 a month for Whey. I just found some for about half of that. Is it inferior some how or is 20 grams of this whey equal to 20 grams of that whey?