I don't have a real 303, I have used the real thing and to me, this sounds exactly the same and that is what you are looking for. Plus it's acid yellow!
That being said, there are other clones out there and the more expensive ones probably have more features. I love the built-in dist, it's the perfect effect for this, but I would have liked a dry/wet mix on it. You can't fade in the dist on this machine.
But, price for sound, this is a 303 and it's super cheap.