Adafruit.com sells the Adafruit RFM95W LoRa Radio Transceiver Breakout - 868 or 915 MHz for $20. They can easily go 2 Km line of sight using simple wire antennas, or up to 20Km with directional antennas and settings tweakings
- Packet radio with ready-to-go Arduino libraries
- Uses the license-free ISM band: "European ISM" @ 868MHz or "American ISM" @ 915MHz
- Use a simple wire antenna or spot for uFL or SMA radio connector
SX1276 LoRa® based module with SPI interface
- +5 to +20 dBm up to 100 mW Power Output Capability (power output selectable in software)
~100mA peak during +20dBm transmit, ~30mA during active radio listening.
- Range of approx. 2Km, depending on obstructions, frequency, antenna and power output
All radios are sold individually and can only talk to radios of the same part number. E.g. RFM69 900 MHz can only talk to RFM69 900 MHz, LoRa 433 MHz can only talk to LoRa 433, etc.
Each radio comes with some header, a 3.3V voltage regulator and levelshifter that can handle 3-5V DC power and logic so you can use it with 3V or 5V devices. Some soldering is required to attach the header. You will need to cut and solder on a small piece of wire (any solid or stranded core is fine) in order to create your antenna. Optionally you can pick up a uFL or SMA edge-mount connector and attach an external duck.
Disclaimer: I do not work for Adafruit or the manufacturer. I have not used this product myself.