for next season I don't think Newcastle will be easy to get into the top four. Considering, although Newcastle have good finances at the moment but they will still find it difficult to sign players who have star quality. Because the star players want to play in the Champions League stage and Newcastle still need time to reach that competition. But indeed, at least over time of course Newcastle will be able to compete in the title race and yes, the Premier League is the most attractive league in its competition and this Premier League seems to be the center for world football.
I agree that money is a very important thing in football, but unless your team already has great players, then superstars won't come to your team just because you offered them a lot of money, you may get that but it is going to be tough. They have a lot of money, what will happen is that they will offer players who do not worth that much, more than what they worth, and get the level of the team higher at first.
Only after that they will be able to get good results, this will be next season, they will be getting top 10 for sure, then they will be able to get some good players, like great level, and that will make them even better, like top 5 for sure level season after that. Only after that, they will get superstars, and that will make them compete for a title. So, I see at least 3 more seasons.