Thanks for the reply. I've definitely considered a 310. I'm leaning away from twins for my first plane though. I think maintenance of most singles will take some getting used to and don't want to throw in the potential financial risk of a twin until the maintenance of a single doesn't make my wince any more. And I'm thinking a twin may be adding more complexity than I'd like.Almost any airplane is only as reliable as your checkbook. Much depends upon how and how much you will use it, how well you maintain it, and how and where you will store it when it's not being used. Short of buying something brand new with a manufacturer's warranty, you can expect an expensive repair to pop up at any time.
With that in mind, there are indeed decent 310s inside your $250k limit. On some of them, you might have to settle for a mid-time engine, or older avionics, but that can still be quite servicible and reliable.
As an alternative, you can have a $500k airplane for $250k if you find a partner. I know several people who are partners on planes, and typically they're getting all the use they want. Depending upon your specific situation and mission, a partnership might be a good option.
And I should say that $250k WITH a partner may be at the top of what I want to spend for now because there's so many reliable option for less than that. Things may be different in the future. I have aspirations of a C340 (or maybe 421) for a future plane. But that would be many years away.