Depends what you consider mainstream - the licensing gouged for everything from HDMI to Atmos, DTS:X, and so on means that there aren't as many price difference

Depends what you consider mainstream - the licensing gouged for everything from HDMI to Atmos, DTS:X, and so on means that there aren't as many price differences as there used to be, so anything above (e.g.) bare-bones Denon will be in the same price bracket as NAD and Anthem (for example). Then you get into the exotica such as Trinnov, Storm, etc.