I recently bought the A-10A by Iris simulation for FSX (if you have FSX anyway), I know it's not quite the same beast but you could use that for ferry flights and then fight the campaign on DCS and fly back. I'm not sure how realistic it is but there is a basic autopilot on that model which means you can at least take a break and leave the sim to fly it.
Only problem is you can't air-to air very realistically on FSX.