I don't recall the K1000 and R-10 being a really big deal when they were selling at retail. The Senn HD600 and Grado RS1s (along with electrostats) were always seen as the mack-daddys. In fact, I remember HeadRoom once had an insane sale where they sold K1000 for $299 or something because they weren't selling. It was only when they went off the market that everyone went crazy over them. Make of that what you will.
If you had extra coin to spend back in those days, you spent it on a kick-ass amp for your HD600 instead of buying an R10. HeadRoom even had a $3000 balanced amp (the BlockHead) designed solely for the HD600 and RS1. Or you bought a $1000 power cable.
It was common for the amp and cables to be way more expensive than the phones. I think headphone makers then realized they were leaving coin on the table and came up with $1000+ super-headphones.
299?! Wow. Why do think the K1000 has become almost mythical in its status?