^ It is possible, but my question is if there is an illegal gambling casino which is you think they are much better than the regulated one, will you still gamble it there? For me, I don't, because most the illegal gambling casino has shady activity, not unless, the government will hunt them and force to stop operation which is very risky if you have a fund on that casino. That is why even how taxes will apply to the casino, they are still preferred this since they are running a business, besides, generating tax must have a calculation per annum and I don't think there is a casino that give more than 80% to the government, usually from 10% to 50% probably.
I don't think people would choose to go for illegal ones even with high taxes on the legal ones simply because being caught means losing EVERYTHING. You already lost money on the casino, but there's another risk of losing everything other than money after all. Not to mention that casinos wouldn't necessarily protect you if they were caught. And really, there's no sense if the difference isn't that much, I don't think that bit amount of money is enough for you to throw away the guarantee that you are playing in a safe environment.