I have contacted a few, and seem to be getting pushed in the direction of maximum spend. My main goal for asking these questions is to know enough so that I can't get jargoned into doing anything excessive for the case at hand.

I suppose the most important answer I am hoping to figure out before I go deeper into it is: Is the SX-200 platform still relevant enough that I should be putting effort into doing a repair versus spending 10-20x on a brand new system. The only thing the owner wants to change beyond just getting outbound calls working again is switching our 7 trunk lines from POTS to IP based, which leads me to think we really don't need to be spending the kind of money for a whole new system when the hospitality industry is... not in the best shape and forecasts are less than sparkly.