Jamie Benn signed a 5-year deal after putting up point totals of 41, 56, and 63. He we improving his point totals every season. $5.25 million per year was very reasonable for those point totals. The Stars were paying for proven talent.
Segun's contract was signed a year after the team won the Cup and he led his team in points. Leading your team in points is a pretty good reason to sign the player to a long-term money deal. However, if the Bruins waited another year they might have gotten him cheaper considering he regressed before being traded.
Tavares' contract was signed after putting up 54, 67, and 81 points. Signing a 6-year, $5.5 million contract was not a risk for the Islanders and was a steal at the time (and still is).
Romi Josi's and OEL's contracts weren't risks at all when they were signed, either.