Second, yes, real estate agents get paid for handling the transaction, and the commission you mention of 6%, while always negotiable, seems within the "normal" range. In fact, Fannie Mae recently issued a statement relating to short sales in which it gave blanket approval for commissions up to six percent for selling a home. So, a major lending institute, even when they are paying the bill, acknowledges that nationwide this is a reasonable fee for residential real estate.
Lastly, I am not sure I understand your question.... attorney hired a realtor and then you asked him to buy the house for half price? Why'd you do that? If you wanted to "give" your friend the house for half price, why was a real estate agent involved at all?