Have never played this game but always wanted to given it's legendary reputation (copies are really expensive). I plan to get the remaster that was announced a while but haven't heard much on it since
Buying on the secondary market does nothing to enrich the original creators, or even the corporation that owns the property.
Especially with games like this, where the only option is to download it, I don't see any ethical issues.
Modern ports and especially Emulation has helped knock down some of those artificial barriers and let people more honestly assess how good the games are.
For example: Panzer Dragoon Saga. I managed to play it on a Saturn emulator. Great game? Honestly, yes. Is it a $500 great game? Eh...
(In retrospect, the failure of the Saturn was really the last nail in the console of Sega's console business, and the Dreamcast just couldn't overcome that inertia.)
Or at least that's what Panzer Dragoon Saga represents to me anyway...