Man with all due respect I dont think we should be giving advice like that to new riders. I know what you mean by get the bike you love but I wanted an R1, Busa & zx14 when I was 18. Even if i had all the money to afford the bike & insurance at that time, I think that would've ended up badly for me. Running before you know how to even walk properly is a bad bad idea. Once you grasp the concept of riding a motorcycle, switching gears, braking, counter steering, lane positioning, leaning & hundreds of other things & master those things THEN I think upgrading to a bigger bike ( Even a liter bike from a 300 ) is still okay if the rider respects the machine.
You can drive a Civic fast and a Porsche slow. Only one person in charge of speed.
Now whether you can control your right hand/foot is another problem.
Personally I don't think I could ride a 300 to it's limits. So is that a downgrade from my current R6?
I hate the term upgrade. Want another bike? Get one, but don't ******** me with this "upgrade" stuff.
Oh yeah, and pay for your toys. If you have to borrow money then you can't afford it.