Rare 90s game?

Rare 90s game? ( bigboxcollectors / Uh-Oh-Raggy ) Hi all. Am trying to find out info on my copy of Cobra Mission: Panic in Cobra City and what it might be worth. This was released in 1992 (still even have the original purchase receipt) and the developer Megatech went under in the late nineties. Have read that the developer gave this an 18+ rating, hence the NSFW tag to be sure, even before the rating system was created and it was the first English eroge game released. Searching for this anywhere to buy came up with absolutely no results but I did manage to dig up some old eBay listings that sold. I have seen a few people in this sub say that sold eBay listing rather than unsold selling listings are a good way to judge the value of a retro big box game, is this true? Don’t have facebook so can’t look at the big box collector group there. Any help to point me in the right direction of more info on this seemingly rare game and I would be most grateful. Thanks! rare,90s,game,rare 90s game