Nah, MS it wouldn’t take much for MS to retake the US. They’ll never beat Sony WW but they can do way better than Xbone did.
We don’t know the prices yet, not much point in speculation. Also weird that you seem to take issue with MS buying studios, yet that “great” Sony first party support is almost entirely reliant on studios they bought. ND, Insomniac, Sucker Punch, GG, Media Molecule, Bend, even pieces of other studios like London came from buying Psygnosis.
You can’t really build a stable of good first party studios without buying. Unless you’re Nintendo of course but they’re the exception to most MicroSony rules.