At his age there's no guarantee his stock would be as high in future windows, especially if he has an underwhelming season. Now that all the big clubs have essentially signed strikers, I don't see what other PL club would opt for him outside of some late Chelsea transfer window shenanigans. I don't think clubs on the continent would be able to afford his fee either. Genuinely think Newcastle is his last shot at a big contract playing both PL and CL football before succumbing to the Saudi swansong phase of his career.