FYI, the Meridian was a notorious underperformer that anyone with an ear ran quickly away from. You can find them for incredible discounts on the used market if any of them are still working. So your "ACTUAL test" was in fact a rigged affair constructed to fool the unwary and uninformed, apparently it succeeded in at least one example.
Revisionist history is cute, but pointless when the record is out there to expose the revisions as false.
Here are the closing comments in JA's technical notes, with emphasis added:
"It is fashionable in some audiophile circles to deride measurements as not having any connection with sound quality. But when you get a player such as the Meridian 508.24, which measures so close to the theoretical ideal in so many ways
, it's hard to resist the temptation to point to its superb sound quality
and say, "There!" At minimum, the 508.24's measured performance reveals that Bob Stuart and his talented digital design team at Meridian have done a fabulous job." Source.
As for current used values, yes everyone should expect a very old disk player to be very cheap on the second-hand market. The more interesting comparison (if you're interested, I could care less) would be to compare 508.24 used prices to those of its contemporaries in the "high end" player market such as the Sony XA7ES, Levinson 39, the Pioneer Elite and Wadia players that were similarly priced when new, etc.
The bottom line is that in a "cheap and cheerful" system, a separate DAC is a total waste of money, unless it offers some serious non-sonic benefits, such as remote volume control or the like. For instance, I bought the Meridian Explorer for my nearfield system solely because it has two outputs. So I can keep my nearfield speaker amp on the volume-controlled output, and keep my headphone amp on the line output. No more need to swap wires. That was worth $300 to me. Were I building to a "cheap and cheerful" budget, adding that DAC (or any other) would've been a massive misallocation of resources, though.