While Cooper had 17.8 yards per catch this past season with the Eagles, Steelers WR Emmanuel Sanders has more career catches (114-93) despite having missed six games over his first two seasons. Clearly two different kinds of receivers, the 6-foot-3 Cooper is a large-bodied target who's eight touchdowns in 2013 dwarf Sanders' career total of five.
That level of deal, though, is likely around the mark Sanders could expect on the open market. It could be a bit higher, given there will be a market that isn't exclusive to one team the way Riley's deal was brokered, but they are similar enough statistically it's a good bet his new deal will be used as a comparable.
Both receivers are products of the 2010 NFL Draft, with Sanders going to Pittsburgh in the third round and Cooper going in the fifth round to the Eagles.
The same could be said for Green Bay's James Jones, who's also a part of a rich wide receivers class in free agency. Older than both Sanders and Cooper, Jones' career numbers, on average, are similar to both players, except for a curve-breaking 14 touchdowns in 2012.
Generally speaking, the availability of all these receivers could lead to a lessened value should they reach free agency as well. Jones' age, Sanders' injury history and other flaws could drive the price down and saturate the market if they are all allowed to leave their 2013 teams unsigned.