I don't think he's "in the market" when it comes to being bought. He's more about committing to something and being able to say he did it better and bigger than anyone else.
He said long ago on many occasions, he wouldn't run for President unless (1) he doesn't see anyone else running that's able to manage the country the way it ought to be, and (2) he's sure he can win. The oldest video I saw of that was in the 90's on the Oprah Show.
Now that he's in the office, he wants to do great. Mostly for the country, but also for himself. At 70, you have to ask why a billionaire who has the life he's got would ever put himself in the crosshairs of the Liberals (and many Conservatives) on a daily basis. It's sure not for the money ($1 per year).
Because he can and essentially give them the middle finger every day.
Again, Trumps says some stupid $hit, but I don't think it is because he's not intelligent. At least I hope not. That said, he says what's on his mind and that's what people have embraced. Whether or not he has ulterior movies remain to be seen, but to be, he basically said "As President, I will do 1, 2, 3, 4, . . . " and he's basically started doing "3, 2, 4, 1, . . . ", albeit in his own way. To me it's refreshing when a politician comes out and at least appears to be living up to his promises as opposed to those who just get elected and press their personal agendas, or even worse, those who financed them.