Edited Sep. 10, 2017 at 1:54 a.m.
Jaccob Slavin versus Tyson Barrie, even with Barrie's atrocious season in Colorado. HERO ratings as people on here seem to value them (we only have one season to seriously compare but we can use two and make it look even worse for Slavin if you like.....)
Slavin = 29 (wins only on shot suppression which anyone would acknowledge isn't the reason you acquire Barrie)
Barrie = 35 (wins on goals & first assists)
Barrie managed to put up decent points totals on a team that was overall horrible, playing as a 1st line D (which he isn't, most people describe him as close to an old-fashioned rover), putting up more points than Slavin in less games on similar ice time on a weaker D corps. Barrie will always have defensive deficiencies. Slavin's potential is in the fact he's better defensively. Barrie is still comparatively young at 26 and in the right D corps will do a lot more damage. That isn't Colorado's, it could be Carolina's. (Carolina are much further along in the rebuilding than Colorado). Slavin IS signed to an admittedly nice contract extension. Barrie isn't and will likely want at least the same money on a long term deal, possibly more if we look at Shattenkirk for a comparable in style if not production (which should increase on the better team). Additionally Barrie has the factor of 4 seasons of either 40 plus or very close to 40 points, so there's a good reason to believe that roughly 40 points per season from the D is going to be an absolute minimum standard. Slavin has one season to look at. (Two if we want to make it look worse). The 'Canes would also get Kerfoot who whilst small was one of the most in demand college free agents for a 5th pick. Carolina aren't the best or deepest at centre and it adds a nice potential option for them.
Barrie & Slavin BOTH top Carlo so really you're dealing on potential after one season for the third ranking D out of the three and the Avs wanting him as a Colorado kid. In return you're getting a young goalie who the Bruins should know from his time in college and has a handful of games experience backing a terrible team so could progress further in a better set up, a nice young D prospect, a 2nd which should be similar or higher than Carlo and a proven roster player and former first round pick in Wilson. Wilson should also be known to the Bruins for the same reason as Martin, and has been a 30 to 40 point producer most seasons. Backes offensive production for almost half the money. Maybe the Avs would take Backes back as a bad salary to make it really even for you and give you more cap room. Be even more of an upside to it for the Bruins. So yeah I'd say more than fair value.
That all said, you will overvalue your team's players in a trade, I will overvalue my team's players. GMs will likely do the same 'til they reach a compromise on value. You should also note the title of the team......for S**ts & giggles!