Even if it really did increase 10%, you'd be giving up a lot of that difference in all of the various costs involved with selling a house and moving, even if you could cut agent costs to $0.
I have some friends who became real estate agents and thought they'd use their position to flip houses while being their own agents to save on costs. They're learning the hard way that even when you're not paying agent fees, buying, selling, and holding homes is expensive.