Managing your money at a casino requires self-control. Nice to see that you have full control over your money reserved for gambling purpose. Successful casino gamblers understand the math and odds behind the games, but discipline with money is also critical.
I think many casinos now are concerned about this and they provide something like vault system to people can maintain their money. and it's true self control is very important in managing anything. Back to the initial point in the betting budget, it all depends on the individual and their goals. if for fun maybe only a few % for their asset but for those who are looking for profit most of them put big capital for sure.