Non-Battery Powered Contact Sensors - Alternatives and Solutions

Looking for non-battery powered contact sensors has been quite a journey for me. I’ve been using the FortrezZ mimo2+ for z-wave monitoring, but at $80 each, it’s not the most budget-friendly solution, especially since I need four more monitoring points. I’ve been searching for alternatives, but everything seems to be battery-powered. Does anyone know of any decent non-battery options? I’d love to hear if anyone has successfully implemented a cost-effective solution or if there are any hidden gems out there. Let’s explore together how we can achieve reliable monitoring without the hassle of battery maintenance. Any insights or recommendations would be greatly appreciated!