I would spend the money and take him in a second, but for a different reason than most.
I have no visions of the Pats becoming a true contender in the next few years. They just won't be. Buffalo is way ahead of the Pats in development, and the Bills and Chiefs will likely be battling for the AFC for a while, with a lot of other pretty good teams in the mix. To think we can plug a few holes and suddenly be there just doesn't seem realistic to me.
What I want to know is if Mac is the real deal. Without hijacking this thread, I think we can all agree we like much of what we saw, but we still don't really know if he's the guy. I want to give him real weapons. I want to give him guys that help him get the ball out faster, making it easier on the line. I want a precise route runner who can help make Mac even more accurate. Most of all, I want to give him all of this and see what he does with it. The only way to answer the question quickly if he will get better with better weapons is to GET BETTER WEAPONS.
Getting QB locked in is going to be the fastest way to get back to where we want to be. If Mac turns out to be a Brady type (he seems to be: accurate passer, team guy, handles pressure on and off the field well), then we can stop plugging in holes all around him and start building an offense for the long haul. If he isn't the guy, I don't want to waste 5 years giving him nothing but #3 receivers and built-in excuses for why he isn't thriving.
The game is changing. Offense rules again. Even the Rams, with their amazing defense the past few years didn't win a chip until Stafford came to town to lock everything down. The Bucs, Chiefs, Bills, Bengals, etc, etc, etc. Great QBs changed the face of all these teams.
We can talk about rebuilding the defense, and I'm not discounting that. But right now, I just don't believe that's the path.