IMO one thing about the value cut-off line might be support. If you spend $700 on an auto from an established manufacturer and you shoot it until it breaks there is probably going to be a parts and/or service option. With a $700 Russian or Turkish O/U maybe not so surely. But probably by that point you will have got your use from it and leaving it behind might not be that big a deal. I shot my SKB 85TSS (one of the Japanese guns) until one of the ejectors broke, it took a lotta rounds and took a long time. I was able to send it back and have it repaired (also upgraded the triggers to mechanical) but back then it cost $500 just to get it fixed up. So it was like an $1800 gun I spent $500 on, throwing away a $700 gun after thousands of rounds is probably not a big deal, if it lasts thousands of rounds.
But when I wanted a 20g the "SKBs" where Turkish replacements, not the Japanese guns with a century of history. I am sure they are great guns but I wasn't interested, they were priced like the Japanese guns had been. So I ended up with a Beretta 686 Sporting, an earlier one with an adjustable comb.
One thing about the O/U depends on where you shoot. Most of my shotgunning takes place where they expect you to pick up your own litter, so the auto is a bit of a PITA.