Yes, but incentive to train your own draftees is only an ANCILLARY benefit of this proposal. The main benefit is to address National Team player salaries which get out of hand quickly. It would mean owners wanting to train NT players would have to invest greater in the draft.
Lebron accepting less money is not the main reason he has a lower salary. The MAIN reason is because of the salary cap in place. He would garner much greater wages in a non-salary cap system such as baseball.
My example of Lebron James was because of the fact that he is the most talented player in the NBA right now. If they didn't have a Max contract stipulation and he went to the highest bidder, it would be an exercise in futility. The max contract stipulation allows team to attract star players while still maintaining enough space to create a roster around them.
Bottom line: If Joe Bronson existed in the NBA he would reduce his asking price to allow himself to stay employed for more than 2 weeks at a time. BuzzerBeater needs a similar mechanism to mimmick this...call it the "Bronson Rule" if you like.