Monoprice has the 4th Gen Apple TV certified refurbished from Apple for $124.99:
https://www.monoprice.com/product?p_id=27950
Use coupon code VIBES for 15% off and there’s free standard shipping too.
This is the cheapest price I could find. I wasn’t looking for the 4K units and wanted some cheap boxes since I just cut Xfinity.