Scott_Hartnell_Mike_Cammalleri

Each offseason, as supply and demand intersect, there are free agents whose contract values rise or fall to an unexpected extent.
This year, seven unrestricted free agent forwards between the ages of 30 and 35 who had NHL salary-cap charges of at least $3.5 million in 2016-17 have signed one-year contracts with charges of $1.2 million or less for 2017-18, making them potential value acquisitions (charges are according to CapFriendly.com):

Benoit Pouliot, 30, of the Buffalo Sabres has a contract with a salary-cap charge of $1.15 million, down from $4 million with the Edmonton Oilers.
Scott Hartnell, 35, of the Nashville Predators has a contract with a salary-cap charge of $1 million, down from $4.75 million with the Columbus Blue Jackets.
Michael Cammalleri, 35, of the Los Angeles Kings has a contract with a salary-cap charge of $1 million, down from $5 million with the New Jersey Devils.
Patrick Sharp, 35, of the Chicago Blackhawks has a contract with a salary-cap charge of $800,000, down from $5.9 million with the Dallas Stars.

Ales Hemsky, 33, of the Montreal Canadiens has a contract with a salary-cap charge of $1 million, down from $4 million with the Stars.
David Desharnais, 30, of the New York Rangers has a contract with a salary-cap charge of $1 million, down from $3.5 million with the Oilers.
Jussi Jokinen, 34, of the Oilers has a contract with a salary-cap charge of $1.1 million, down from $4 million with the Florida Panthers.

That's an average salary-cap charge of $1 million for seven players whose average was $4.45 million last season. The combined value of their salary-cap charge is 22.4 percent of last year's, and is within $350,000 of the League minimum salary, $650,000.
According to the underlying numbers, these players can provide solid secondary scoring and help drive possession, making their cap charges appear unusually low.
Over the past three seasons, each of the seven forwards has scored at an average 5-on-5 rate of 1.5 points per 60 minutes or above, according to HockeyAnalysis.com. That figure is roughly the threshold for a top-six forward, in my interpretation. In particular, Hartnell's 2.16 ranks No. 19 among the 404 forwards to play at least 1,000 minutes in the past three seasons, according to HockeyAnalysis.com.
Based on data that goes back to 2009-10, each of the seven players has boosted his team's share of all 5-on-5 shot attempts. For example, Jokinen's teams have been responsible for 51.6 percent of shot attempts when he has been on the ice, and 48.4 percent when he wasn't, for a relative SAT percentage of plus-3.1 percent. Hartnell is also at plus-3.1 percent, and Sharp is at plus-2.9.
Statistically, the contributions of these seven players go beyond scoring and shot-based metrics. Jokinen has won 53.4 percent of his career faceoffs, and Cammalleri has won 51.8 percent, each ranking in the top 100 among players (58th and 96th, respectively) who have taken at least 2,500 faceoffs. In the shootout, Desharnais has scored on 41.5 percent of his attempts (17-for-41), Jokinen on 39.1 percent (36 for 92), and Hemsky on 33.3 percent (21-for-63). (The NHL average last season was 31.4 percent).
Even when analytics are set aside, it's hard not to picture the immediate benefits of adding a player like Sharp, who has scored 30 goals in a season four times and has won the Stanley Cup three times, or Hartnell, who holds the distinction of having no active player ahead of him in both career penalty minutes (1,727) and points (683).
Each of the seven players can make a wide range of contributions, and has potential value that is likely to far exceed his cap charge.
Yes, there were some forwards between the ages of 30 and 35 who received contracts with higher salary-cap charges, like Martin Hanzal (age 30, $4.75 million) and Alexander Radulov (age 31, $6.25 million) of the Dallas Stars, Justin Williams (age 35, $4.5 million) of the Carolina Hurricanes, and Brian Boyle (age 32, $2.75 million) of the New Jersey Devils, but those have been the exception this season. In general, forwards in their early 30s have been available at an apparent discount.

Among the remaining free agent forwards between age 30 and 35, Thomas Vanek, 33, Drew Stafford, 31, and PA Parenteau, 34, could garner the most interest as possible high-value additions.
With 38 points (15 goals, 23 assists) in 48 games, Vanek ranked No. 2 on the Detroit Red Wings in scoring when they traded him to the Panthers on March 1, 2017. In his career, he has scored on 28 of 67 shootout attempts (41.8 percent).
In 2015-16, Parenteau ranked second on the Toronto Maple Leafs with 41 points (20 goals, 21 assists) in 77 games, and he has scored on 20 of 46 career shootout attempts (43.5 percent). In terms of shot-based metrics, Parenteau has a career relative SAT percentage of plus-3.4.
Of the three, Stafford adds the greatest defensive component, having averaged at least 1:00 per game killing penalties in three of the past six seasons.