invest that money in something you will use to exercise instead such as really good comfortable supporting shoes or some weights for home etc.
The best shoes you can buy for weights are the cheap copies of the converse all star. $12 from target. I have had a pair of flat everlast slip ons for about 3 years they are great. Cost me $100.00.
Dave i will disagree with you on the glutamine thing as well, I find it great for sport.