Risto certainly is not going to be cheap. 25 year old big, strong good skating RHD who is on pace for his FIFTH straight 40+ point season even though his ice time and PP time has been significantly reduced. Risto leads the Sabres in hits (has double the 2nd placed player), is 2nd in blocked shots, is a tough strong Dman with snarl, and is a good PKer. After going -41 last year he is currently +2. His +/- is literally PLUS 43 BETTER. Has a player ever put up that big of a positive difference before?!?
Risto is only available for a 2C. He is not going to be given away. Unless Carolina is going to give up 1st+good prospect that can be immediately flipped for a 2C I highly doubt he is going to be traded. Buffalo has kept Risto this long, they are not going to give him away now.
I agree he won't come cheap but more that he's available imho. Buffalo seems to have soured on him and made him more available than he should be.
Also, your argument wasn't as sound as you made it out to be. 40pts, awesome. That's a solid argument. Blocked shots, hits, and +/- are the 3 worst stats to use. Decreased ice time and less PP led to a better +/-? Why yes, that's typically how it goes. Any player forced to play a role above his head is going to have a bad +/- especially if they are getting lots of PP time where +/- isn't recorded. Blocked shots means that shooters get shots while you are on the ice, see Calgary's blocked shots before and after Peters (or earlier Carolina's blocked shots before and after Peters). Modern NHL has players get sticks in lanes and challenges shooters more than NHL from 20 years ago, lots of blocked shots often shows a player is too slow or too out of position to challenge shooters. Hits is the opposite of blocked shots, it can be a sign of a player playing too aggressively or not using stick checks effectively. Outside of role players, hits often carries a negative analysis nowadays.
I'm not discounting Risto, there's a lot of stats from this year that show that he's excelling in his current role after struggling when put above his head before he was ready for it.
The factors that make Risto available though are
Buffalo reported offering him before + Buffalo struggling with asset management + Buffalo's place in standings + Buffalo feeling pressure to create success