Evans will get an elite contract not because he is an elite player but because somebody will pay him "elite" money just because he will be the best WR available. Did anyone in their right mind think Berneard Berrian was a 7mil a year WR? I sure as hell didnt. In the NFL today you dont make what you are worth compared to similar players at your position you get paid based on what other options are out their for teams that year. If Evans hits the FA market regardless of the fact that he has never been to a pro bowl he will most likley be the best WR on the FA market. When a team is desperate for a WR they will overpay to make sure they get the guy...... then the following year another WR will start the negotiations at that number. There is a reason that Larry Fitz makes so much more than Anquan Boldin and its just because his contract was gonna end first not because hes SOOOO much better of a player.
If the Bills are smart they will realize two things
1. Pay Evans because anyone you would try and sign to replace him you will have to overpay anyways so you may as well keep the guy that you already know is talented.
2. Pay Peters whatever he wants plus a free fruit basket to make sure hes happy because he is THE single most important player on this team, and because you are going to set this franchiseback ten years if you lose him.