Are you considering a small single head or three head machine or are you thinking of like a large candy bar size machine?
My husband and I used to have a three head machine that we placed at the place where I worked. It paid for itself over time, and we made a few dollars profit from it each month. It had gumballs, Reece's and peanut M&M's.
We bought it at Sam's Warehouse.
Eventually, it got destroyed during a flood (completely freaky random occurrence) but it taught us a few lessons.
It's a volume game. You need multiple machines to make a consistent income.
You will need to do the ground work for placing and stocking the machines.
Be prepared for loss. (Again where it comes into a multiple machine games).
We never did anymore, since we didn't have the time for the placement part of the process (our jobs didn't leave us with time during the week during business hours.) But it's a proven moneymaker, if you can do the groundwork.