Do auto mechanics take unfair financial advantage of women?

I just bought a new car because my old one was diagnosed by the dealer to be in need of costly repairs that far exceeded the value of the four-year-old car. So, rather than throw good money after bad, I bit the bullet (in this failing economy) and opted for a new, inexpensive economy car. I justified the purchase because my gas charges would be cut in half by the new economy car. Since I commute a long distance daily, the monthly fuel savings would cover half the cost of the monthly payment on the new car.

Also, my neighbor who is a mechanic for a local dealership, privately bought my old car for what I thought was a fair price. He said since the old car needed work, he would pay me what it was really worth since he could fix if for very little. After all, he is a mechanic, and he seemed to be fair and honest, so I sold it for the retail wholesale blue book value, minus what he said it would cost him to repair it.

After both above transactions were complete, I learned from a personal friend (also a mechanic) that he would have fixed my car for half the amount I was quoted by the dealership; and, as if that fact is not bad enough, he also said he would have bought my old car for twice the price my neighbor paid.

Now I ask you, do male mechanics take unfair financial advantage of women?