It's like convenience store competition, and hence I would put my vending machines in secluded stretches of walk ways to get people hydrated with their loose shekels. Like the canal near my home doesn't have any vending machine, but the park does. So I would rent a spot off the canal because I feel that people with money in their pockets who are thirsty would quench their thirst for a 2 dollar 12 fluid ounce can of energy drinks.
https://www.amazon.com/Red-Bull-Energy-Drink-Sugarfree/dp/B001E14104/ref=zg_bs_g_16318341_d_sccl_9/142-9413664-4803363
Redbull cost roughly 1.50 a can, so you charge it for 2.50, and make 24 dollars off a single case.
https://www.walmart.com/ip/Red-Bull-Energy-Drink-114mg-Caffeine-12-fl-oz-Pack-of-4-Cans/10316267
Walmart sells them at a cheaper price if you buy the 12 pack conferrable to the 24 pack.


But that's nice you could resale items with just a 80%-200% markup, and if you are a nigga like me, you would use gibs to pay for everything so it's all profit.