I love the difference in cap philosophy highlighted by this signing.
The reason the Bills couldn't keep their up and coming RFA was because they're tight against the cap, after seriously overspending in Free Agency in the last few years, for an underperforming DL, a TE that amounted to Meh, and assorted big-name bits that played way below their salaries.
So, their homegrown kid, who was new to football when he first came into the league, but was flashing the potential to outplay a number of Buffalo's early round draft picks at WR, comes to the Patriots for his prime years. It's another case where by Week 10, fans from opposing teams will say, "how do they keep finding these guys?"
The Pats, on the other hand, spend their cap space on team depth and underappreciated players coming into their prime. And they get criticized during Free Agency for "being so passive". Doesn't seem passive to me... just seems like they have a different idea of what value looks like.