I'd rather give Bradley $9m a year than bring in Eric Gordon.
The pure rebuilding trade for Boston would be to send Humphries to New Orleans, Gordon goes to a third team, and the Celtics take on non-expiring contracts from that third team that New Orleans doesn't want, in exchange for draft considerations. Guys like Bogans or Brooks might also be involved. At least one first, more than just one first. That's the kind of trade that a rock-bottom, talentless team should make, but I think the Celtics have too much talent on their roster and should instead be aiming to make the playoffs next season.