Why do QR codes cost money?

QR codes only cost money when a service keeps working for you after the code is printed. A static code is just a picture — generating one costs nothing, and good generators give them away free forever.

A dynamic code is different: it points to a short redirect URL hosted by the provider. Every scan hits their servers, which must stay online for the lifetime of every poster, menu and sticker ever printed — plus the dashboard where you edit destinations and view scan analytics. That infrastructure is what the subscription pays for. So you're not paying for the square of pixels; you're paying for the ability to change where it points and to see how it performs. If you don't need either, don't pay.