I've worked in bars for a long time before, during, and a little bit after study. I've even worked in Australia for a year.
By increasing the cost of alcohol, when people finally have enough money to buy it - they won't just have a little bit. They will have way too much. The harm and financial burden you're looking to minimise will actually INCREASE. Australia is a perfect case study for exactly this.
We have vastly more responsible laws than Australia (e.g. we feed intoxicated people, they send them outside to cause trouble). But that is not nearly enough to offset the problems this will cause.
Find another way to fix this issue. Preferably one that is backed by reasoning and reality. Germany is probably a good place to look to for inspiration.
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