America is an amazing place, where you can get your learner's on just about any bike. Europe is very restrictive; I think you can only start on a 125. Here in Australia, it used to be a 250 limit, then a 500 limit, and now a 650 limit; but there are weight-to-horseppower limits as well.
But all in all, I think you would be beter off starting on a 250; such as the Kawasaki 250 someone mentioned, or the Honda Rebel, or the yamaha 250 Virago, if you prefer the laid-back style.Most experienced riders would not look at these bikes; but if you are totally new to riding, you will learn much more easily on one of these.
An advantage is that you can pick up fairly recent second hand models of these bikes quite cheaply, and then if you move up to something larger (like the Honda CBR600Fi or the Suzuki SZ650 - a great all round bike), you will get most of your money back. I actually got more for my Rebel (called a CB250 in Australia) than I paid for it, and sold it before I got my licence (the Australian rider's test is quite difficult, and would be difficult for a beginner to passt on something like the CBR600Fi).
Those who start on a large capacity bike either have natural talent and interest in riding fast; or if not, they are asking for trouble. Even my 'sedate' Yamaha FZ6 could do 220km/hr, and my current bike will do 0 - 60 in less than 4 seconds. Sure, you don't HAVE to ride these bikes fast; but a twist of the wrist at the wrong time, and you are in serious trouble.
Without further raving, I suggest starting on something smaller that won't break the bank, and from which you can move up to something larger pretty soon - when you discover what sort of riding you want to do.