POS System for Small Pharmacy

I run a small pharmacy that focuses on over-the-counter medications and I need a straightforward point-of-sale solution that keeps the day-to-day workflow simple, reliable, and fast. Right now I accept cash only, so the software should let my staff record cash transactions quickly... (Budget: $10 - $30 USD, Jobs: Cloud Computing, Database Management, Inventory Management, MySQL, PHP, Point of Sale, Software Architecture, Visual Basic)