I'm not sure it would work to make it expensive, I've lived in London for a while, and tobacco products are very expensive there, they were expensive for me, I knew few Ukrainian guys I would buy cigarettes from, for 2-3 pounds a packet, while I had enough money to buy 13 pounds cigarettes after I found a better job. I know a lot of people from when I was there, they were still buying cigarettes from those Ukrainians. You make gambling expensive? I'm sure lower classes can find someone who can let them gamble for cheap. I am no libertarian, but I think when it comes to vices, it's a lost battle, prohibition works for a the better-off part of the population, it leaves the one who need government the most, outside the government reach. I'd say things should be legalised, but money shouldn't be spent for anything except help programs, social programs, better working conditions for those who suffer and find peace in gambling and/or drugs. Legalising gambling was probably a mistake, but it was a way to keep it out of reach of organised crime.
I think being born and raised in Naples, I've lived all my life in direct contact with organised crime, but many people live in places and don't make the connection, but I'd suggest everyone who think about regulating or not, to keep in mind that in any place you're in, there are 2 governments, one you can see, and one you can not