I have that same mount you’re referring to as I needed a 1 1/8” scope height and was able to get it at a bargain for only $200. 
This mount for my XBR cost more that some guys pay for their scope!
Armalite makes one without the 20 MOA for $90.
http://www.maxicon.com/guns/optics/one_piece/ar15_onepiece_mounts.htm
This mount for my XBR cost more that some guys pay for their scope!
Armalite makes one without the 20 MOA for $90.
http://www.maxicon.com/guns/optics/one_piece/ar15_onepiece_mounts.htm