I agree, start smaller - that way when you screw up, and you WILL screw up, you won't also have to deal with that numbing, "OMG, I spent how much $$$$$ on this thing?" feeling.
As for scale, though, I wish I had started out with 1/350 just to learn how to not screw up as much ... but living in a small apartment, 1/700 seemed like the only viable option.
The nice thing about ship modeling (OK, I admit it, I'm weird) is the delayed gratification factor - a ship doesn't really start looking like a ship until you're almost done with it, because a ship model is basically a collection of sub-assemblies that end up perched on top of a hull. I was well into the home stretch of my rebuild of the USS Enterprise to her 2006 configuration before I started to get that, "Yeah, now we're getting close!" feeling. I was building it for a friend whose daughter, a brand new ensign, was shipped right out on a six-month deployment that ends next week. When I took it over to her yesterday and started pointing things out to her (she knows nothing about ships, the Navy, etc.) she just sat there, slowly stroking the side of the hull with one finger, then started to cry, saying for the first time she understood what her daughter was doing and why. That made it all worth it.