The Marlins don't want all the Sox contracts you don't like for Stanton. The one they might not mind is actually Castillo, because Cubans do have a certain marketing appeal in Miami.
But the rest of that trade would have to involve giving up players you prefer to keep. Think of giving up three from Devers, Benintendi Groome, and Chavis. Otherwise if the Marlins are going to be spending all that money, they would just assume spend it on Stanton.
If you wete GM of the Marlins, would you trade the best hitter in franchise history for Price, Hanley (who wore out his welcome in that city once already) and others? If you would make that deal, any chance the Marlins will hire you in the next 3 days?