If Beasley were in New England he would produce at least as much as Amendola, and possibly just as much as Edelman. Further, as jiggy noted, the Patriots offense depends big time on Gronk being a mismatch, much like we depend on Dez being a mismatch. If you remember last year they started 2-2 or whatever, were blown out in Kansas City and people were wondering if Brady was done, that was because Gronk was out, they only started hitting their stride when he came back.
Beasley is not a good punt returner and I'd be fine giving someone else a try back there, but he's still the same WR he was last year, with a healthy Romo and Dez he'd be producing.