Advice is a dangerous gift, even from the wise to the wise (with a tip of the hat to J.R.R. Tolkien).
Purchasing an airplane may work out just as you have calculated ... and it may not. As a first time airplane buyer, you don't know going in. I have owned Juliet for two years now, and she is my first airplane. I got very lucky and she has been very trouble free, but, still, I have learned a great deal.
When my wife asks what a repair is going to cost, I usually respond, "Oh, it will be a few bucks". What I don't say (though I figure she has figured it out) is that I am referring to "airplane bucks". An airplane buck is about $1,000.
It would not take too many mechanical problems to render your financial justification for buying an airplane moot. Of course, there are other reasons for buying an airplane besides financial...
You don't mention your lifestyle. As you are probably figuring out, flight training is a lot of work. So is owning an airplane. You need to spend some time taking care of it. An airplane is more like a boat than a car. There are always little niggles that need to be addressed. That attention will draw time and attention away from your training. However, If you are retired that kind of thing may just add to the fun.
I rented airplanes during my flight training. But I was running a business at the time (I still am, for all of that) and being able to drive out to the airport and jump in the airplane when I had time to fly worked well. Sombody else got to worry about the oil changes, low tires, fixing the "squawks", and making sure things were all secure when the weather turned ugly.
When I came close to being ready for the checkride, and I knew that I had the fire in the belly to fly, and I also knew I would be basing myself at an airport where there were no rentals available, I made the leap into airplane ownership.
If you rent, you know what your costs are going to be, and somebody else gets to hassle with keeping up the airplane. If you live close to an FBO with rentals available, I think I would stay with that.
On the other hand, if you are just DYING to own an airplane, and you can afford it, what the heck! A 150 couldn't be a better choice. But I wouldn't expect the finances to work out quite as you have outlined. In fact, I wouldn't use finances to justify the purchase of airplane under any circumstances.
Reg
