The Patriots have traded for and benefitted from premium cornerbacks before - think Darrelle Revis. If it gives us two years of premium play and Ramsey never sees the back end of the contract because he wants to get traded again, so be it. That's a price I'm willing to pay. Ramsey would bring this defense up to another level with his physicality and size.
Edit: Just saw that the Dolphins got Ramsey. It's gonna be a lot harder for Mac Jones against Miami, and that's a team that already gives us a headadche.