How would you set up your own independent pharmacy club/cash discount club?

Walmart has the $4 list Walgreens has Prescription Savings card club. How would an independent pharmacy set up a similar club? Say you wanted to give your club members a $10 charge on a regularly priced $34.99 medication if they are part of the club (assuming no insurance contracts) Would you simply change the price at the register, or would you have to set up an entire system where you create a bin, pcn, and ID number?
Source: Student Doctor Network - Category: Universities & Medical Training Authors: Source Type: forums