It all really depends on what you want to do… I mean, if this is a one-off in a controlled environment, and you don’t need to build a whole backend for managing payment etc. then I would look into using the PN532 with your own custom antenna winding (to get batter performance with the xNT)… wire that into an Arduino … or use a Raspberry Pi with ACR122U (which does pretty well with the xNT already) that you can also connect to an external network for management purposes… and then interface some I/O pins with the vending machine’s “acceptor/validator” in some way to allow the vend to proceed after successful scan.
If this is a business idea, then I would need to know more about the concept before proceeding… PM me and I can help consult on the idea.