As a side note, in my experience when someone "outgrows" a small bike that fast, all it means is they have to slow down to a crawl to take any sort of corner (because they lack the skill to navigate it any faster than a snail's pace) and make up for it by hammering the throttle on the straights.We've all just seen it before where someone "out-grows" their "learner" bike in a year and goes right for a Super Sport. Usually doesn't end well.
I challenge anyone who thinks they "outgrew" a 300 in a year or two to go up against some of the small displacement racers and see how much they still have to learn about the limits of the bike.
If you want a bigger bike because you want a bigger bike, that's one thing. If you think your skill exceeds the limitations of the machine, in almost every single case I believe you're either lying or oblivious.