The max you can save on Koskinen is 1.025M on the cap. He will still count for 1.475M if in the minors.
In that case, the Oilers would have Montoya as backup, who is currently at 1.0625M.
So sending Koskinen down likely means adding $350K to our cap.
The first two lines are correct, the math is wrong though: You're forgetting to subtract the bury-able cap from Montoya's contract when he's in the minors, where he costs 37.5k against the cap. So sending Koskinen down and bringing Montoya up would actually add pretty much the full non-bury-able cost of Koskinen to the cap hit. 1.4375M to be exact.
On the other hand, the Gryba buyout perplexes me. Why he gave him a 2 year deal in the first place perplexes me which is now stretched out to a 3 year deal essentially.
Yeah, this buyout was baffling. Two ideas thrown around were:
1. Frees up a roster spot
2. Opens up ice-time for other prospects
1. Seems minor, maybe we do need that spot to fill out the full roster including two way contracts (not super familiar with the bakersfield lineup), doesn't seem very significant.
2. Give more ice-time to prospects. Why not just sit him in the press-box though and give the ice-time anway? This leads to a third point:
3. Maybe they don't want him around their prospects at all because he's a slow clutch-and-grab dinosaur that might teach bad habits?