Systems, methods, and devices for conducting sales transactions are provided. Embodiments include handheld, portable, electronic, point of purchase devices configured to acquire identification information from articles to be purchased, to determine a purchase price, and to acquire payment information for the purchase price. The point of purchase devices may include one or more input devices such as a near field communication device, a camera, a scanner, and a biometric sensor for acquiring the identification information and/or the payment information. In some embodiments, the near field communication device may be detachable from the point of purchase device. The point of purchase devices also may contain communication interfaces, such as a near field communication interface, a local area network interface, a short message service interface, and a personal area network interface, for transmitting the information to an external server.