If you are looking for affordable smart switches, the Tuya devices are very affordable alternative and the can integrate with your openHAB instance.
Complete Guide Connect Tuya Plug To OpenHAB and Home Assistant Using Tasmota
How to Connect openHAB and Tuya Devices - The Smart Home Blog
Linking Tuya Smart devices - Bindings - openHAB Community
Wie Sie Tuya in openHAB mühelos integrieren!
How to Connect openHAB and Tuya Devices - The Smart Home Blog
Step-by-Step guide for adding Tuya-bulbs, Wi-Fi smart LED (Smart Life app) to OH2 using tuya-mqtt.js by AgentK - Tutorials & Examples - openHAB Community
How to Connect openHAB and Tuya Devices - The Smart Home Blog
org.openhab.binding.zigbee/org.openhab.binding.zigbee/README.md at main · openhab/org.openhab.binding.zigbee · GitHub
Smartlife/tuya and tuuya-mqtt - Beginners - openHAB Community
How to Connect openHAB and Tuya Devices - The Smart Home Blog
Using Tuya Smart Products to Empower SME Smart Home Solution Installers - DusunIoT
Install Tuya Binding with the 3th Party Methode - 3rd Party - openHAB Community
LSC smart devices - Installation - Home Assistant Community, lsc smart connect