I agree with sosh. Besides the write-off, alot of people lease because that is their only option to "own" a car that they otherwise could not afford. If you are in a position to buy (which is what it sounds like), and you either don't plan on taking a write-off for the lease or can't legitimately qualify to take the write-off, then you should purchase.
I don't know a single person who was happy with the way things turned out at the end of their lease (with the exception of the "write-off" category folks). They all seem to go over the allowed mileage or have something else happen that ends up making the lease option far less attractive than the buy option in hindsight.
Also, at least for me, it would be AGONIZING to have to write out a $35,000.00 check for what is at that point, a three year old car, at the end of the lease that you are talking about.
That's my humble opinion.