It's always advisable to all gamblers to use money that are being attached to something meaningful for gambling because sometimes the money the is meant for important thing could be lose while gambling.
That is why when we are going to play it is Important to see how much money we are going to play with and that money we are willing to lose, that is the key, there is no other way , we are people who in order to act in money matters must plan, and as it is so difficult to determine whether we will Win or not the most logical thing to do is to allocate the money we are willing to lose.
Sure you are right and that is what should be implemented as gambler. You know many people aren't that mindful on how much they uses for gambling but one thing for is that they must lose if they don't use the right money that they can lose to gamble and when they lose it then it becomes something of regretting because it shouldn't be used for gambling.
However, timing is also important while gambling this would help us to manage our bankroll properly, as it's bankroll management is another major thing while gambling because many people after allocating the amount they are using to gamble you would see them placing bet at once with all the amount they have funded and when lose you see them complaining for losing their bankroll.