Think some need to step back here and see the bigger picture...(pun intended

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For a start not all equipment is the same or performs the same....but that depends on what aspect you want to compare..... Reason for an expensive BD player ???..... maybe there is, and maybe I am a potential customer !!!!!!! (Shock horror).....
So set up one, uses AV amp and a BDP to stream to it, so effectively we are using the player as a transport, like the days of 2 box CD players..... sorry I pre date AV, and digital !!... So stereo/HiFi is my game.....
So now the difference is only going to be in the read ability of the drive. In audio this had an effect due to Jitter and reclocking needed. In AV I can't believe the jitter would be so bad in modern players to cause any issue.
So no need for an expensive player in this set up.....
Set up 2....(possibly like mine).... The AV amp doesn't have HMDI, and or the need to switch video etc. either way the user chooses to do the decoding in the BD Player........ Ahhhh NOW we have all those hours of R&D and cost counting for something,,, As the on board dacs for both video and audio are being used.
Now the question should be, what is better, 1000 BDP and hi end analogue AV pre amp, or 300 BDP in to 400-800 AV amp ? (Typically what people buy).
My pre amp is a 5 channel analogue Hi-Fi amp, with DACs onboard for DD and DTS. With no HDMI, on component video switching. So is out of date from a tech point of view. For sound, it has no problem to win a demo.
So for me the Hi-End players "could" offer something, with their onboard processing. I actually think for me this is the better route to take, as I don't need to compromise the rest of my audio system this way.
Not everyone has the same requirements.......but of coarse everyone opinion is always right !!!......