I disagree. If you've got get a 50cc, get something cheap. Don't waste your money on shit that wants look like something that it just can't be.
Better save that money and get a real bike when you're old enough.
Get a used Zündapp or something, the shittier it looks, the better. It'll be cheap, just as "fast", easy to maintain, and certainly more unique.
There's nothing wrong with an Aprilia RS50 as long as you don't buy one new.
Always wanted one, but ended up with a silly Peugeot Speedfight instead.