At the Post Exchange New (Military) Circa versus Retail (Depends on store...) New:
Sansui CP-7: PX = $550 / Off Post = $675+
JVC PC-5: PX = $580 / Off Post = $700+
Sanyo C9: PX = $330 / Off Post = $400+
JVC M90: PX = $400 / Off Post = $500+
Kenwood DC20 El Poco: PX = $750 / Off Post = $900+
JVC PC-55: PX = $700 / Off Post = $850+
Pioneer CK Series: PX = CK3/$400, CK5/$550, CK11/$700 / Off Post = CK3/$500, CK5/$680, CK11/$850+
(I owe a big ups to my dad who has been an "official" technician since 1964 after turning 18 (at 16/17 he would make his money under the table)...he worked on all of these as a long time technician for AAFES as well as the civilian side...)
Could go on but why? Heck I remember going into the Lerche Stores as a kid in Stuttgart and seeing Telefunkens in the ridiculous realm...even at 4.50DM to the dollar at the time it was scary.

Even mediocre boxes were going for dumb prices given the performance at the peak of the era.