When Ali was getting started in 1960, wrestling was in a decline, and was taken less seriously than boxing. It was also still segregated.
I'm having a little trouble finding a really reliable source, but the figure being frequently given for George Wagner is $100,000 per year - at his peak. While Ali's early earnings were small, he was making good money within a few years.
By '64, he was making six figures per fight.
So, I have serious doubts that he would go that route. But, were he to actually do so, he'd be giving up both money and fame.