My opinion is that the only way to fix NIL + transfer portal issues is to do it w/ proper contracts at this point, same as NCAA coaches. These contracts would also have proper buyouts if a player decided to leave (could have clauses for entering NBA draft as well), but in general would run the length of a player's remaining eligibility.

For example:

Let's say a lower-end P5 / Upper end G5 school gets a commitment from a solid player, and they sign a 4yr deal worth 1 Million dollars ($250k/yr). That player blows up his first year and wants more $$$. He has two options: Option 1) Both player and school can come to terms and agree on an amended higher contract for the remaining 3 years. Option 2) Player decides to go to a bigger school, but the bigger school must buyout the contract. Let's say it was equal to the remaining pay ($750k).

Even if it is option 2), the buyout has a significant benefit to the smaller school. First off, it gives them much needed cash to compete with the bigger schools (and potentially find another player with the buyout $$$). Second off, it "disincentivizes" bigger schools from poaching the smaller school's player unless it's really worth it, because they not only have to pay a higher base "salary" for the player, but also have to pay the smaller school's buyout.