I'd have no trouble trading one of the fifths for him (rather than spending it on a rookie QB), but it is reported that New England wants a Day 2 pick after drafting him last year with a sixth.
What I'd offer is a conditional pick next year. If he makes the roster, they get a fifth. If he makes the roster and is the No. 2 QB, they get a sixth. If he starts two or more games, they get a third. If he starts nine or more games, they get a second.
That would give them incentive to trade him and give us some control over what pick they get.