Too much for McDonagh (essentially 3 firsts and a fourth) and too much for Grabner (first for someone with only 18 non-EN points and bad possession stats). The Nash trade seems more than reasonable (throw in the playoff games played condition that way the Rangers don't still get a first if Nash gets injured and misses the playoffs) and the other two trades are minor

Best comparable trade is keith yandle. Yandle got a roster player, the rangers #1 prospect, 1st rounder and second rounder. McD is a better defenseman than yandle (overall not soley based on offensive output) so he would fetch at least that, so the vegas trade essentially plays out fairly.

Condition for nash should be reach conference finals not stanley cup and there should be another condition for resigning him as well

Let's compare this to the Yandle trade. Yandle was an offensive defenseman who was the same age McDonagh is now and had put up 41 points in 63 games with Arizona that season. The year before he put up over 50 and had 30 points in the lockout shortened season. He was the best offensive dman available that year, similar to Shattenkirk last year. The Rangers gave up John Moore, who they had given up on (and the Coyotes did too after only 19 games), Anthony Duclair who was a third round pick and had played only 18 games, a first and a second.

Now lets look at the Shattenkirk trade which yielded a decent prospect, a lower prospect, a first and a conditional pick (would've been a 2nd rounder). The Caps also received a promising goalie prospect in this trade, so Shattenkirk's value was a little bit less than that.

Given those two trades, there is no way McDonagh is worth 3 first rounders and a 4th. Maybe if he was in his early or mid 20's he would, but he is 28 and has only one more year left on his contract