I think this is ignoring the diminishing returns on the talent gap between players. The talent gap is going to be much larger between the #1 player and the #51 player than between the #51 player and the #101 player. Boosters would be much less willing to spend that much on the #51 player to appear in a car dealership commercial when they could get a relatively similar talent level for the #81 player.
But overall, I think @Pistol‘s point is still the most salient. Kentucky and Duke already overwhelmingly get the best players available. Even if blue blood boosters start paying to get the best of the #51-#100, the overall parity with the rest of the sport would improve, just by letting the top go pro, in my opinion.