You were responding to a post by Two Ears (DACs become obsolete quickly) by saying most of the high end stuff retains their value. What I'm saying is most DACs become dated and their value plummets at a faster rate than other types of source (CD. TT). Even the high end stuff.
This is pretty obvious to whoever keeps tabs on the secondhand market. Couple months ago I was looking for some new gear to try out, and my first choice was the Accuphase DP700 - which was released in 08, and retailed for around 12000 in Japan. They still go for about 9k on the used market- not bad right? Now check out the prices on the MSB Platinum DAC IV series, which was released a couple years later than the DP700.. pretty much all are sold at half MSRP, or less.
I guess there are some high end DACs that retained value longer than most (Audio Note UK and Wadia comes to mind) and maybe those that have limited supply (Kondo KSL-DAC), but most of the time selling this stuff secondhand is like sitting on ship with a leak. You either throw away most of your goods or everything just sinks faster.