I believe that the poor player should always risk less, because if he loses 1 month of salary he will most likely not have a financial reserve to compensate for this loss and consequently he will have to ask for a loan or stop paying a bill to continue "living" in the next month.
The rich individual is the one who can afford to risk more and still have a sizable amount to fall back to. That cannot happen with someone not earning little or nothing at all.
The individual earning less when gambling responsibly, would obviously nothing or risk very little if he must. Not entirely the same case with the individual earning good money and can afford to risk quite a bit and not go broke if the risk undertaken do turn out favorable.
If you don’t have the means to risk more, you just won’t be able to.