The feasibility of this sort of operation has been done to the death on here before. The introduction of JAR and EASA has made it completley uneconomical to run a single aircraft of that size on an AOC - the charges and the infrastructure are essentially prohibitive for one aircraft.
Suggest you have a search around the BizJet forums for similar threads.
Ops costs of a Cheyenne? Could make an educated guess at being more than the cost of chartering a similar machine (if such a similar machine is offered for charter now!) - but it's related to hours flown. Anything less than 2-300 and charter would be cheaper. It's a rule of thumb that works at the higher levels and I'd be surprised if it wasn't applicable at this level, though am always willing to concede.