Part of the ultra-upper end of the 1st gen' players at 250,000¥ - same pricing as the Sony CDP-701ES, Yamaha CD-1 (both bestsellers), or Diatone/Mitubishi DP-101.
A player I have never seen and know almost nothing about : it didn't sell at all, wasn't exported outside Japan and was very quickly replaced.
I doubt very much Onkyo had (then or now) the industrial clout to make an original - I don't know who made it or OEM'ed the main parts for Onkyo : Kyocera ? Sharp ? Sanyo ?
The image here shown comes from a unique september 1983 japanese ad.
An interesting design nevertheless with a huge tray which takes almost half of the total width and looks much more like... a turntable !
Big beast at any rate : 14 x 43cm and 14kg - heavier than a CD-1.
Since posting this page, I have managed to find the original japanese catalog ! It isn't scanned yet but you can see it here.
It isn't a "talkative" catalog, though, it is in b/w, too, and it seems Onkyo put as much care building the DX-5 than... forgetting about it.