I edited my reply before you quoted it.
Yes price have absolutely nothing to do with it. You may get lucky to find an amp that suits the k712 for far less.
The 500 dollar plus amp is a guarantee though. The headbox or the chord mojo to name two in that price area.
Anyway, I get that people choose the 800s over the k712 I'm simply stating that with proper amp matching the k712 far exceeds is 250 dollar price. That was my only point really.
I do NOT agree the k712 is for home use where did you get that idea?? Considering you have to go amp hunting its a terrible choice for anyone except a professional or a audiophile that gets it.
The hd800 is surely much easier to find an impedance match given its high impedance.
Oh and plenty of users have stated they prefer the k712 over the 800s i didn't just pull that out of thin air.