At our space we have a "part time" price that most people are on - we assume 2-3 days per week, but we don't count.
We also have a one day a week plan, and a drop-in rate.
On top of the regular part time, we have a "plus" plan that essentially gets you a mailbox and a parking space.
So few people use our copier/printer, we never bothered to put the code on it to count per person.