The category engine doesn't need to have pistons, so...
4-ROTOR 26B NATURALLY ASPIRATED
650 HP
10,000 RPM Limit
Late 13B side housings
Full Peripheral Port
Fully Dynamically Balanced
Ceramic Apex Seals
Race Bearings
Blueprinted
$39,525 USD
https://www.definedautoworks.com/maz...s-4-rotor.html
Seems reasonable.
A welcome return to the glory days of the Australian Touring Car Championship, that were arguably unfairly cut short.