interested, it's near-identical sibling is in the geq. The well-known Sontec and 'geq' are literally from the same schematic of a transformerless mixing desk that was never made by either designer.
I believe there is now a nice, but slightly different, reissue of the Sontec, same, but new organization of the same developer, but now we are talking about cost based on name and other factors, in my opinion.
The "G" is an amazing eq for mastering or truly anything, and it costs a lot as a result. But, the Sontec has risen to the cost and status, in my opinion, because of the extreme rarity. Service was near obsolete, parts impossible to find, few people that could replace with suitable options. The price should be equal or less than the "g" for a new one, again in my opinion. If the tables were turned and all replaceable materials for the 8200 suddenly vanished, I would imagine it would jump in tag value as well. Not as much as the Sontec, though, considering that the "g" has been in production, steadily, and reliably, for the same duration that the Sontec has had its many issues. From what I've read, and this is from research and not my hands on, that the first battle with a good Sontec example, of the favored model, is finding two in nearly the same condition. The second is whether the preference is in the aligned, misaligned, or otherwise upgraded or serviced qualities. One person prefers the high end 2% more than a "g", where another finds it grainer or harsher, where a third comparison shows one Sontec much steeper than another, and yet a different source much, much smoother, almost too soft, thus it must be a differernt comparison than the one having the 'sweeter' highs. I think that the right, original, serviced, Sontec, would be an awesome addition.
Thank you so much for the thorough, thoughtful, and informative reply!
You can probably tell (from the other topic I started) that I'm looking at a nice mastering EQ to add to my arsenal. I'm definitely looking at the GEQ, but had also heard wonderful things about the Sontec.