HackRF One from Great Scott Gadgets is a Software Defined Radio

peripheral capable of transmission or reception of radio signals from 10
MHz to 6 GHz.  Designed to enable test and development of modern and
next generation radio technologies, HackRF One is an open source
hardware platform that can be used as a USB peripheral or programmed for
stand-alone operation.

- 10 MHz to 6 GHz operating frequency
- half-duplex transceiver
- up to 20 million samples per second
- 8-bit quadrature samples (8-bit I and 8-bit Q)
- compatible with GNU Radio, SDR#, and more
- software-configurable RX and TX gain and baseband filter
- software-controlled antenna port power (50 mA at 3.3 V)
- SMA female antenna connector
- SMA female clock input and output for synchronization
- convenient buttons for programming
- internal pin headers for expansion
- Hi-Speed USB 2.0
- USB-powered
- open source hardware

HackRF One has an injection molded plastic enclosure and ships with a

micro USB cable.  An antenna is not included. You can purchase an antenna here.  

Price: $399.99