Can you give some examples?
Right now I'm looking at a pair of pair of Telefunken 6922/E88CC 1960-1961 on tubeworldexpress.com for $500. This is Brendan Biever's site (USA) that he moved over from tubeworld.com. Best tube dealer I know for over 20yrs although Andy Bowman is tops for 6SN7.
Marty is right, there are a lot of fine sounding 6DJ8/6922/7308 that are less expensive than the above example - if you can find them. The whole family keeps getting more and more expensive.
First thing you should do is read Parts 1 & 2 of
Joe's Tube Lore written in 1999, posted on Audio Asylum. This is an excellent write-up. Wanna know what he says about the Telefunken 6922?
"Telefunken 6922 / E88CC (with shield, diamond bottom, gold pins) Slightly hollow mids, not as rich as the best Siemens and Amperex. A bit like the Siemens E288CC, though a bit better than that tube. A good tube, but the more common & cheaper Siemens 6922s are much better choices IMO. (Absolutely pounds the Russian tubes, though!)"
That was 1999 and the 6922 and 7308 were far more plentiful then though still somewhat scarce.
This is what Brendan wrote on his original tubeworld site:
"The Best Sounding 6922=E88CC ever made are:
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6922 Amperex Holland "Pinched Waist" 1958, many branded Valvo
6922 or CCa Siemens Halske 1950's - 1960's (airy highs, great detail, solid bass)
6922 or CCa Telefunken 1950's - 1960's
6922 Amperex "PQ" Holland Gold Pins white printing 1960-1966 (older the better)
6922 Amperex Holland branded Amperex or Philips Miniwatt or Mullard Holland
or Philips Holland "SQ" 1960's
6922 Mullard 1960's
CV2493=E88CC-01 Mullard late 1960's to mid-1970's
6922 Amperex USA "PQ" white printing 1960's then orange printing 1967-1972
GB-6922 Sylvania GOld Brand Gold Pins 1960's
6922 Sylvania, many are branded RCA 1970's - 1980's
6922 Tesla Gold Pins - older stock (very good value)
I always bought top quality 7308s when I could fine them. Here's Brendan again:
*7308 Amperex Holland "PQ" white printing with 2 Stars on tube 1959 - 1960
7308 Siemens 1960's - 1970's
7308 Philips Miniwatt Holland 1958-1972 (the first series had 2 stars on each tube)
7308 Telefunken 1960's
7308 Mullard 1960's - 1970's, many have dimpled disc getter halo
7308 Amperex PQ USA white printing 1960-1967
7308 Amperex PQ USA orange printing 1967 - mid 1970's
7308 Amperex JAN and USN-CEP-7308 Amperex white label 1960's
7308 Sylvania JAN and Philips JAN USA late 1960's to early 1980's
7308 Siemens 1980's (avoid these, poor sound, all have getter halo on single post in center of tube)
* best 7308 I've used
6DJ8s don't last as long, are usually cheaper, and some sound fantastic. And again:
6DJ8 Siemens West Germany 1960's (nothing beats this tube; accurate, open, focused, detailed, airy, tight bass)
6DJ8 Amperex Bugle Boy Holland "D" getter 1950's (superbly musical 6DJ8, nice articulate bass, 3D sound)
6DJ8 Telefunken West Germany 1960's (a little bass shy, but superbly smooth and listenable long term)
6DJ8 Amperex Bugle Boy Holland 1960's
6DJ8 Amperex Holland 1960's and Amperex Holland Globe Logo late 1960's - mid 1970's (some are branded Philips Miniwatt)
CV5358=6DJ8 Mullard 1960's (smooth, good bass, the older versions are the best)
6DJ8 Mullard 1960's (either branded Mullard or Philips or Amperex Great Britain)
6DJ8 Sylvania late 1960's - mid 1970's (excellent sound for the money, best value)
6DJ8 GE USA 1960's - 1970's (good value)
My Lamm M1.2 Ref monoblocks take a single 6DJ8 family tube each so I only need two - which gives the opportunity to experiment. Here's a few from my box that should be less money than those Telefunkens and sound really good. Some tubes are definitely better than others in general and in specific components.
6922 Philips SQ Holland 1971
6922 Siemens 1965, branded RCA
Amperex 7308 Holland