I think it’s more odd in the other direction. Tambaqui has been out for several years; how the hell does it seemingly retain so much resale value in such a fast-moving segment of the market as standalone DACs?
Asking 65% of full MSRP @ $13K, on a 6 - 7 year old DAC in used condition (no matter how recently purchased - it’s used), seems almost absurd in this market. Chord Dave is another one that’s retained very high value for a very, very long time.
I suppose both makers have done an excellent job at controlling the distribution chain (pricing controls) until now. The recent influx of "like new" units in the secondary markets might be indicative of a new model / revision soon to come, meaning this is distributor / dealer stock that’s finally being dumped ahead of that announcement (i.e. these could be actually new, B-stock, or dealer demo units that are now being distributed outside normal protocol).