I tried that a couple of years ago (tried both vanilla and chocolate and got it at Sam's Club). It tasted absolutely nasty. Then I saw a while ago that they re did the flavoring so I bought another 5 pound bag and it was 1,000,000 times better tasting than the original stuff. It's a pretty good price too at Sam's Club. I also used EAS Whey protein for a few years when Sam's Club was selling it. Actually I think I may have seen some smaller 2 or 3 lb. bags at Sam's Club the last time I was there. The EAS vanilla tastes like @ss but the chocolate is OK.
Just out of curiosity, how much did it cost?