This Saudi strategy is not something that will last long without failing. So far, Ronaldo is serving as a bridge for more players to accept playing in this league, and since the Arabs are offering a lot of money to the players who accept playing in this league, so for now everything is fine. But in this league, the only motivation the players have is the money they earn. They are not striving to win individual awards, they are not striving to be famous, so when the day comes that Ronaldo retires and the Arabs no longer have much money to pay the players' high salaries, the league will die, it will go back to what it was before Ronaldo appeared.
Saudi Arab is an oil producing country and is very rich, so the question is that they won't be able to pay more to the players is out of the question as they have ample money to give it to the players to keep the league running.
Ronaldo coming to play this league was the first success for this league and they should focus on getting more better players to this league even if they have to pay more.
Also if the rewards for winning the matches are increased and individual player performances are rewarded with money, i am sure the players will be more keen to show better performance and hence we see more quality football in this league. Yes, it is only the money that is required and will keep this league running for long term.