U-Turn was/is a "business opportunity" styled enterprise where I feel corners were definitely cut to move units. These machines are notoriously unreliable, difficult to service, and thanks to unusual proprietary parts (doggedly protected by Uturn's lawyers) the used market for parts is wildly more expensive than for other machines of the era.
Some key failings on the Uturn machines include the vending mechanism (they are made of plastic, and once broken are very hard to repair), the cannisters (cracks are a common problem), and the coin mechanisms themselves. There are scores of videos on YouTube of people purposefully breaking Uturn mechs so that they freely spin and pour all the candy out. Even without deliberate interference, the Uturn mechanisms can be broken by something like a washer or a stack of coins jammed in and spun hard. Once a mechanism is broken, they are incredibly difficult to repair, and even then they are never quite right again.
Now for the subject, the legendary "50 cent mechanism." If you look up past posts (like 2013 or so) this was a hot topic as these mechanisms were already fairly rare back then. Today I don't even know how one might go about getting any- unless Uturn has suddenly made a new crop of them in the last few years, I'd put them next to unicorn tears and Half Life 3 in terms of availability.
In short, a vending machine business is a fun, inexpensive business for kids to get into, and I applaud your efforts to make that possible. That said, I would implore you to consider the deeper cost of the machine you are looking at. Many machines are more expensive up front, but cost very little in the long run with reliable components that aren't likely to break, and can be readily and inexpensively swapped if they ever do, while other machines may cost a lot less up front, but then cost exponentially more in the long run in repair costs, your time and effort to maintain them, and finally the lost sales from machinery that doesn't work properly all the time.
If you do go forward with the Uturn, we'll be happy to help you however we can- just know what you're potentially getting yourself into.
As always, good luck!