Yes investing is worth it, I have invested a lot and gained a lot of profit, but anyways its very low to be honest.
It is only low when you invested only low, try increasing your investment and you can rip the fruits of you labor in the future. My tip is if you have only few coins or money try to invest in a casino where not yet known to the public as you will have a good percentage of sharing in the pot money.
You are right, invest low earn low, and invest high earn high,
By the way the OP is deciding a good amount to invest in gambling $3000 is too much to invest in a casino, he mush have to start with a lower amount , it will be better for him and with that he will check himself.