I don't understand the anti-broker hostility. Brokers do not "jack up the price" to the buyer, they "jack down" the proceeds remitted to the seller. The market determines the sales price, it's up to the seller to determine if he wants to deal with it himself or pay the broker to handle it.
I bought my Navion through a broker (Wisconsin Aviation) and have no regrets. Amusingly one day at Oshkosh I was standing at a friend's Navion waiting for him to return and this little old man walks up to me...
HIM: Is this your airplane?
ME: No, it belongs to a friend of mine. But I own an Navion as well.
HIM: I used to have a Navion, but I had to sell it a few years ago. (he pulls a picture out of his wallet).
ME: That's my Navion. You're Harry Deutch, aren't you?
HIM: Yes.
ME: I bought the plane from you.
Alas, that was when the plane was not there being in restoration from my engine failure. I did send him pictures of the restored aircraft when it came out of restoration.