When I was a teenager in the 1980's, it was extremely difficult for minors to buy alcohol where I was. We used to drive around for hours trying to get a 6 pack of the Beast and some wine coolers for the girls.
But that all changed when I was 17. I got a completely bulletproof fake ID. It was literally a valid FL drivers license with my face on it and a 21 year olds information. I quickly became known as the guy that could get booze for people guaranteed with no hassle. Even during the school year, I made $40-$50 a week just charging a mark-up for that service, which was a tidy sum for a 17 y/o in 1986. Pretty girls got discounts on the mark-up and were always free to barter services for the goods.
The summer between my Jr and Sr year in HS I did not even work a job. I would just spend a couple hours every day raking people for the booze I bought for them. Another advantage was that I always knew what was going on, where the parties were, and what girls would be where. That was valuable information to have and not easy to come by a decade before cell phones. The school drug dealer and I were the only ones to even have beepers.