Why are Marantz receivers priced higher?

Marantz Cinema 50 9.4-Ch Receiver (110W X 9) - 4K/120 and 8K Home Theater Receiver (2022 Model), Built-in Bluetooth, Wi-Fi & HEOS Multi-Room, Supports Dolby Atmos, DTS:X Pro, IMAX Enhanced & Auro 3D

Marantz SR5009 review: Stellar sound in a classy package

NR1510 - Slimline 5.2 Channel AV Receiver with 50W, 4K and 6 HDMI Inputs | Marantz - US

SR7015 - Featuring 3D audio, HEOS® built-in, 8K/60Hz pass-through, and voice control. | Marantz - US

PM6007 - Slimline Integrated Stereo Amplifier with 45W | Marantz - Canada

HEOS update for Marantz and Denon - Son-Vidéo.com: blog

Best Stereo amplifiers 2015