The demo of Stereo-mix and Surround Version of the Rieger-Esztergom Organ has a limited compass of C2-C3 (048-c to 060-c) in the pedal, C2-G5 (048-c to 079-g) in the manuals. All other functions work.
Rieger-Esztergom stereo-mix version.
(It contains only the stereo mix version)
The price is € 89.
Rieger-Esztergom premium version
(It contains wet and dry and six-channels surround version)
The price is € 129.
Rieger-Esztergom Upgrade from stereo-mix version to premium version
The price is € 40.
I suggest you buy only after trying the demo