Are you planning to charge for diagnostic procedures? For example if I use a chest-XRay intead of a CT-chest scan, it will be cheaper. It can influence the overall hospital budget or partnership with insurance companies. (I think it could be an important aspect of the game)
While I expect this will get tweaked quite a bit when we get to balancing the game, yes, the cost of procedures will play a role, just like their duration (which then translates to a part of the salary you pay your doctors).