Well, his cap hit was mainly irrelevant when he was on LTIR, right? So that would seem to be neither here nor there.
Objectively speaking about the regular season only, Price of course. wasn't worth his contract as the NHL was entering a non-goalie dominant era. Only the Habs seemed to think one goalie was worth that term. Nobody really was / is anymore.
However, maybe it's better to look at it this way: They made the Stanley Cup Finals. How far would they have gone that (or any) season without Price? My feeling is that they wouldn't have even made the 'play in' ー and certainly wouldn't have won that and other rounds ー with an average goalie instead of Price. And with another goalie, they had to pay him, too, to the tune of maybe 3 or 4 million, which you can then subtract from Price's salary.
So the question then becomes: How much revenue was directly or indirectly generated for the franchise as a result of that Cup run? And then how much of that extra revenue was attributable to Price being in net?