I ended up finding the CENTRALITE PEARL THERMOSTAT 3157100 used on eBay for about $30. It can either operate from the panel or through ZigBee, no WiFi. It is supported on Zigbee2MQTT. It works really great and I have had no problems with it. You can easily find a manual for it online too.

That would be awesome. I wish banks would also have standardized (or at least open) APIs so I could use FOSS financial software to pull my live purchase history and then categorize that and etc. I think some banks do this, but not very common in the US from what I can tell.