I got your point. However, please not that (state sponsored) lottery, scratch-offs etc. have waaaay worse payout than blackjack or roulette.
If you go to a casino, you go in order to be entertained (yes, partly pay someone to play cards with you, but also): watching dressed up people lose and win money and observe how they react to it and experience the thrill of occasionally winning yourself. Now, if you go with the intention to make a fortune, you will be most likely utterly disappointed.
When I am in Vegas, my method is to put $200 in my right pocket and play with the money from that pocket. All winnings go straight from the table to the left pocket. When I am out of money from the right pocket, I leave. I count how much is in the left pocket and being a mathematician muse about the probabilities. I have a good time either way! (I primarily go to see shows though.)