There are many many people who have heard the difference between a fixed cost Stereo and an equal cost AV Receiver. AV Reciever typically have under-rated power supplies. A 700w AV Receiver will typically have a 500w Power Supply. There is logic behind that, but it doesn't change the fact that it is true. A typical 200w/ch Stereo amp will commonly have a 300w Power Supply.
How can you expect limited heat sink space to serve 7 amp, the the same heat sink space serves two amp in a Stereo.
Plus you have all the additional complex electronics found in an AV Receiver that you don't have in a Stereo amp. That degrades the per amp channel price even more. Even with economics of scale, you just can't expect a $50 to $60 amp to equal that of a $250 amp. No degree of economics of scale adds up to that.
But, an AV Receiver does have some advantages - Electronic Bass Management, Ease of connection to video related equipment. However, there are Stereo amps with built-in DAC and Network Streaming that minimize this difference.
If I have a choice between a $550 Yamaha AV Receiver and The $550 Yamaha RN500 AM/FM, Network Streaming, DAC-optical, coaxial, USB-media, 80w/ch, I'm taking the RN500.
If I want to go hard core, I will take the Yamaha AS500 85w/ch ($399) and a separate DAC. Or the Yamaha RS500, 75w/ch, AM/FM, plus an external DAC. Likely the external DAC will give me both USB-media and USB-PC as well as Optical and Coaxial.
Or the Harman Kardon HK3770 ($449) with 120w/ch, DAC (24b/192k) -Optical, Coaxial, USB, Wireless and Wired Network Streaming, Bluetooth, Massive Power Supplies, AM/FM, Phono.
Or the Yamaha RS700 with100w/ch for $499, plus an external DAC.
I have no interest in diluting my amp with many amps that I will never use, or diluting my speakers over many speakers that I don't need. However, I have nothing against other who do what to do these things. And I admit that there are connection advantages to a AV Receiver, but it is not the equal of a similar priced Stereo Amp.
Now if your AV Receiver is price up around $1500 or more, then you are into pretty nice amps. I heard some FOCAL speakers play on higher end AV Receivers and they sounded very good. But I would not expect that same sound quality on a $500 AV Receiver. In a $1500 AV Receiver each amp is worth about $215. With a $2000 AV Receiver, each amp is worth closer to $285, so reasonably they would sound like it.
But, if you are going for a 2.0 primarily music system ... then get a music system, meaning a stereo. Though if you actually want an AV Receiver - your money, your life - do as you please.
Steve/bluewizard