It seems to vary on price depending on condition though. I have been following the e-bay listings for over 13 years and the price point is about right for what was listed.
I've been following online listings for Turbo/PCE games, including eBay once it began carrying the games, for 18 years. I don't know what you mean by "listed", but Ys I & II (and III) has consistently sold CIC in decent+ condition for $30'ish for the past couple decades.
Over the years I've encountered countless drama threads asking "Why can't I find Ys I & II (or often Ys III) for under $100!" Each time I say the same thing about what you can regularly find it for. It is only after being called a liar, do I usually bother doing a recent eBay search and have never not found results that back it up, even with normal things like droughts, spikes, etc.
My previous post was based on a very narrow search of recently
sold copies on eBay, of which there are a lot that are CIC (including insert) which went for <$40 - $50'ish. But there were also "complete" copies like these:
$26$29.99Ys III CIC $29.99"As high as" prices are useless to buyers of complete-enough games-to-play. They're only meaningful to sellers looking to raise the price ceiling.
For example, if someone asks advice on what to pay for Keith Courage, telling them that they can
buy it right now for $45 isn't helping them.