Should I use a Real Estate agent to buy investment properties?

I just bought my 1st home and now want to start buying some investment properties. I am looking to invest maybe $100K (real money) per year for a few years, so maybe buy $500K worth of properties per year. I was thinking of buying properties myself and because of the tough times just saying that I want 1/2 the agents fees in the contract for myself.

I however am in my 20's and know little about real estate investing. I do wanna learn it for myself and definitely have a mind for it. I do know a very good agent that I trust but it feels wasteful giving $15,000 that I could keep to someone else per $500,000 I spend. I just wonder if it is worth it because I could make a mistake worth a lot more than $15,000. Driving myself around and setting up appointments seems easy enough though and my attorney (my good friends dad) could help me with negotiations?

Any and all advice is appreciated.