I haven't used a vending machine in a while. They usually just have overpriced junk food and if I'm gonna eat junk I might as well shop for a good price to pay for it. But you and I both know how the machines work. Success works the same way.
You identify what you want
You pay the price
Wait for your payment to go through (you know, the little metal thing turning)
[Sometimes -- You shake the machine up or bang on it a bit in addition to your payment. A little extra "oomph" finishes the job]
You get your prize
Sometimes, someone pays the price and leaves before their prize dispenses -- either they lacked the patience or didn't bang on the machine hard enough. So guess what the next person (you) gets? Two prizes for the price of one.
Sometimes someone tries to get the prize without paying: they tilt the machine trying to get something for nothing and the machine falls on them and they suffer broken bones or death. Don't be this person.
Sometimes what you paid for doesn't taste as good as it looked, it's stale or you lose your appetite before you get to eat it. That's fine - just choose a different prize and pay that price. That's life.
Either way, nobody eats free. But you are all welcome to look through the glass and admire the goods.