Best and Cheapest way to get 14 contact sensors?

[Cobra]

I have had a lot of success with these tiny things...

https://www.gearbest.com/access-control/pp_626703.html

Drivers for Hubitat

[Deprecated] Xiaomi / Aqara ZigBee device drivers (possibly may no longer be maintained)

NOTE: Although many users have had great success using them, Xiaomi / Aqara ZigBee devices are NOT officially supported or guaranteed to work on the Hubitat Elevation platform. I am maintaining a collection Xiaomi device drivers for Hubitat in a GitHub repository, at veeceeoh/xiaomi-hubitat. These device drivers are based on the bspranger/Xioami repository of device handlers for SmartThings, but with significant modifications and improvements for use only on the Hubitat Elevation hub platform. …

Andy