Early tube gear by Marantz, McIntosh, Brook, Radio Engineering Labs, etc. have appreciated greatly, not just due to inflation but due to the fact that they are historically important classics and collectibles, as well as being impressive performers even by today's standards.
Saul Marantz sold his original company in the late 1960's, and the "Marantz" brand that has been around since then has only the name in common. As was alluded to, it has been a Japanese company in recent times.
McIntosh was sold to Clarion in 1990 and D&M Holdings (Denon, Marantz and others) in 2003, but they have continued to produce products along the same evolutionary lines as before.
Mark Levinson lost his original company and the rights to use his own name in the early 1980's, following financial problems and power struggles. The successor company, Madrigal Inc., eventually became part of Harman International. Although solid state, the original products of Mark Levinson Audio Systems are considered to also be collectable classics, and that is contributing to their appreciation.
I think that if Classe equipment is holding its value better than other makes that are not in the category of collectible historical classics, then it does indeed say something about its quality.
Regards,
-- Al