You know, re-reading the original post, I don't think I need to sell the Mitsi, it practically sells itself. You could get a nice Marquise for well within his range (I think, don't keep up to well anymore), whereas anything else that will do the mission will be junk at that price. Although you might want to look at an "L" model (-36) if you can find one. Same basic cabin as the Marquise, a bit slower, but cheaper to acquire and with better useful load since it's not lugging around those massive props (they didn't bother to up the gross on the Marquise, which I never understood). You do get a bit more fuel with the Marquise, but the range isn't much greater due to the thirstier engines. IMS, 1000 miles is going to be right on the edge of what it can do westbound.
As to it being difficult to fly: Frankly, poppycock. A non-idiot, properly trained, can fly it just fine. The basic rule is get to 120 as fast as you can and don't go below 120 until you're pretty close to landing. FWIW, it was my first turbine-powered aircraft and I stepped up from a Baron. Didn't crash once in ~1400 hours, and I am not, contrary to popular belief, The Greatest Pilot Anyone Has Ever Seen. Don't tell.
PS. Of course if you want a type rating and he owns an oil well (and maintenance shop), you could probably get a fairly nice old Diamond jet for that sort of money, too...