There are some bargains out there if you know what to look for. The thing is on these 6n23ps - they almost never come in matched pairs from the Russian/former Soviet block dealers. So you have buy batch after batch and make matched sets yourself. I hope one day they get wise.
Spoke to a US tube dealer and one in the UK. I asked them why they don't carry these '70s 6n23p. The answer - they only want large blocks of tubes (say 500) - and those are just not available in the '70s. Where as they can find blocks of Siemens, Amperexs, Mullards, and Telefunkens - except the rarest kinds.
So it's back to the dark lit alleys of ebay!! Ugg!
thankfully there someone out there digging for us !!
listening to my russians right now !!