Seems like a stupid plan as much as an immoral one.
Wouldn’t the father expect that at some point his son would be discovered to lack the requisite skills to play college volleyball?
Also, a quarter-of-a-million dollars would have paid for the entire room/board/tuition/books for a four-year degree at this school.
“Honest services fraud” is a phony crime in a case like this. Nobody was defrauded by any objective definition of “fraud” in these cases.
As you correctly pointed out ... these people ended up paying MORE for a college education than a “legitimate” student would have paid.