Well, after all I've read before and including this thread's wealth of information, I have to come down opinion-wise on the side of the use of synthetics. The better the oil, the better the maintenance.
Granted, it really don't matter to your pocket book if you're planning on trading frequently anyway, but that's like saying that since your company requires you to move frequently, there's no point in doing preventive maintenance on your house.
Vehicles are complicated pieces of engineering. As savvy discriminating consumers, we choose the best we can afford and because of that we love our machines. Sure, we use them and abuse them in the use for which they were intended, but we don't neglect them.
I guess the point I'm dancing with is that one is not only the owner, but also the custodian. We live in complex technological matrices, not barefoot agrarian nature walks. As part of our pact with our tribal matrix, we purchase, inheret or acquire the control, benefits of ownership, and responsibility for objects that are the quantatative result of thousands of man hours of labor of our fellow tribesmen, to keep for such time as they are needed by us, and then pass the remaining value on for others to enjoy.
Though we may not dwell on it much, when trading time or selling time comes that extra money spent on preventive maintenance, realized or not, is still in the vehicle.
Thankfully, due to the availability of synthetics, my life's schedule doesn't revolve around 3,000 or even 5,000 mile oil changes. I want the longest safety factor built into the oil I'm using. That way, I can think about oil changes with the passing of the seasons, instead of the accumulated milage.
Twice a year, Spring and Fall is my schedule, needed or not.