In gambling, you can use any amount, But i suggest you, first you should see you pocket, I mean better is that use small amount in every time in gambling. Because in this way, if you lose so you can afford it and instead of it, if you play big bet and think if you win than it will be a good for you, But in fact it is useless way, because you can't afford it.
That's why we call gambling is a risky way, and also you want invest you amount, So why not you play gambling. It is best way for experience wise.
Right it is really risky .in gambling you must know when to stop is hard to know whether you will win or not so better risk only what you afford to lose so that you will not regret in the end. Set your limits , value it often. Then made a goal for yourself for example creating some milestone that if you reach a certain profit/ loss, you will withdraw already your funds on the gambling site and already stop betting for that day, In that way you will have a goal to control your loss.