For most thrift stores today, an iPad or tablet-based POS system is preferable to a traditional cash register. Tablet POS systems are less expensive, more mobile, and easier to set up and use. They also take up less counter space and can provide useful features like inventory management, customer profiles, and sales reporting that a basic cash register lacks. However, a cash register can still work for a very small thrift store and may save on costs. It comes down to your specific needs and technical abilities.