If you are looking for affordable smart switches, the Tuya devices are very affordable alternative and the can integrate with your openHAB instance.
How do I connect tuya smart plugs to openhab? - Beginners - openHAB Community
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
The Ultimate Smart Home Starter Guide, by Martin Thoma, Geek Culture
OpenHAB 2 and RaZberry - Blog
How to Connect openHAB and Tuya Devices - The Smart Home Blog
LSC smart devices - Installation - Home Assistant Community, lsc smart connect
How to connect to OpenHAB with Dusun gateway? - DusunIoT
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
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