Mark II shutter reliability

I recently found myself a 2nd hand 1D Mark II, which had been used mostly for studio photography. I then opnened Photoshop to tell me how many actuations it had. The answer was about 25K. But later on, I found out that Photoshop might not be the right application to use for that purpose, as 1Dcount gave me a number of 91K.
Anyway, the camera works perfectly and looks fairly good (couple of scratches a few places only). So my question is, do shutters live shorter if getting used in a specific way? Or can they break down at any given moment?
What's the price of a new one?

well they are rated for 200k I dont think anything makes them die faster then another unless maybe it wasnt cared for and got all kinda crap in there to muck it up. But you said was just used for studio so none of tat would happen. just like any electronics..it might be rated for something but can go at any time really. I think a new one is $200

OK, maybe it helps if I don't worry about it?