Hi All,
If you want a cheap WiFi to ble gateway a raspberry Pi Zero W can be used with ease and send the raw data packets via MQTT.
For a 4g gateway Gl.inet are about to release the x750 iot gateway, it is a 4G gateway with a BLE module. It’s should fit into your price requirements. The information can be found at:
https://blog.gl-inet.com/gl-inet-made-its-first-appearance-at-cebit-2018/