The question is also over what period of time this happened? I think, it is doable to go from zero to $5000. But it just takes more time, than starting with a br of $100. Of course it is also depending on how much you play daily. For beginners in my opinion the best br is to start from zero by freerolling. If you are experienced player and open a new account in a room, then you should transfer what you need to play your limits comfortably. Or maybe also what is needed to cash out some first depositor bonus, also depending on how much you are able to play.