It's funny I was looking at some Citations for sale last week, out of boredom, not shopping.
Anyway, you can buy a pretty nice I S/P with fresh hot sections for $400K, that gives you 1500+ hours to OH, assuming a scrap value of $100K. That's $200 per hour for the engine cost over the 1500 hours, you would still have maintenance issues, but the engines themselves wouldn't likely need much spent on them for the remainder of their useful life.
So you could fly a Citation to the junkyard for $400 per hour plus fuel.
Exactly. The most economic operations of any vehicle is the operations taking it to the junkyard. Those are the deals to look for. Since avionics are pretty much transportable, upgrades can be amortized into the replacement plane.