Thank you for asking!

So, it may give a random item and the user won't know what it will get.

No you got it wrong / I described bad. With this vending machine you will know what you buy. It was just my attitude to build up some "what could it be?" in the game. So this machine is like you said:

... sell crypto tokens using in-game currency, mostly tip tokens and utility tokens. One can sell tickets to special adventures in the game as well.

But your thought I had too about another vending machine. Do you know these capsule vending machines? Also a funny idea.

Greetings!