Actual LoRaWAN gateways based on Semtech SX1301 concentrator can be pretty expensive, and even if you take a LoRa gateway design based on Raspberry Pi for indoor placement or experimentation, price is still around $200.
A much cheaper way (~$70) is to use a single channel LoRa gateway, which as the name implies only support one channel, which limits the number of nodes, and forces you to set the nodes at the same frequency as your gateway. Those are not really suitable for commercial offerings, but if you manage your own gateway and nodes that should be usable. If you only plan to implement a network with a dozen nodes or so, you could even use much cheap ESP32 LoRa board like the ESP32 LoRa 1-Channel Gateway sold on Sparkfun for $29.95.
- WiFi and Bluetooth 4.2 LE via ESP32-WROOM-32 module with integrated PCB antenna
- LoRa @ 868 / 915 MHz with Hope RFM95W LoRa modem controlled via an SPI interface + u.FL antenna connector
- 14x GPIO ESP32 pin-breakouts
- Qwiic connector for Sparkfun modules
- Debugging – Via micro USB over a CH340C USB to serial interface
- Misc – Reset and ESP32 pin0 buttons; power and user LEDs
- Power Supply – 5V via micro USB port
The board is open source hardware with resources uploaded to Github, and the company also provides a detailed tutorial showing how to configure ESP32 1-Ch LoRa gateway board with The Things Network (TTN).
That’s not the only single channel gateway solution as cheaper TTGO LoRa boards have also been used for that purpose with the code for the gateway and node pushed to Github, and a four parts video tutorial uploaded by Vergil Cola explaining how to get started, and get the data to TTN.