It's definitely possible for certain people to reach higher levels of play in a shorter period than others. I've seen several players pick up tennis early in high school and go on to play college tennis after their senior year. I would say they were 4.5 to 5.0 level players. So beginner to 5.0 in about 4 years is pretty darn good. But 1 year? I don't see that happening.
The most important thing to consider is also not time or money spent training, but natural ability. If you have amazing hand-eye coordination and athleticism, then you might be one of those guys who can climb relatively high in a few years. But if you lack in either or those areas, you'll probably never get there. So make sure you realistically evaluate your abilities before dumping a bunch of money into this quest. There's usually one of these types of threads on TTW every year, and most of the time the player wastes a bunch of money and we never hear from them again. Though it does often provide a lot of entertainment. And you can't always put a price on that.