HereForTheBeer: First, I suppose you meant "lack of supply". Lack of demand should lead to lower prices.
Right. Since they see the dwindling amount of copies as a reason to raise the price, and since those who will buy such games are likely collectors in their eyes, the prices are yanked up.
HereForTheBeer: Disliking the offered price is not justification to get it for free. Instead, the consumer can A) do without (life goes on without playing Game XYZ), B) wait for prices to come down, C) wait for the game to make its way out of Legal Hell and into digital distro venues, and D) click the Make Offer button and ask for a lower price.
Of the four options, the first is practically the easiest. B would sometimes be waiting for hell to freeze over, C is more likely but still something remarkable with today's publishers either only focusing on the new or remastering what has been already avilable for years. And D, is, well, uncertain, and that entails in the next point I want t omake.
HereForTheBeer: On the question of whether you're getting what you want, returns, etc. This is actually somewhat better than buying a brand-new game on gOg. For a title purchased on gOg, if it works but isn't what you wanted, then your options are actually fewer than if you bought it on eBay. On gOg, you're not getting a refund if it you don't like it. For eBay, maybe - you can claim it didn't work, etc. The chance for a return on an eBay purchase might be small, but it's still a better chance than if you don't like the game you bought from gOg.
With eBay, the chance is
uncertain. I may get a return. I may not. With GOG, it is
certain what gets a return and what won't. The money back guarantee if a game doesn't work after fixes is one such measure and the ability to refund games that you haven't yet downloaded is also there. With eBay, it might as well feel like gambling my luck.
HereForTheBeer: If the publisher doesn't want your money... doesn't matter. We like to use DRM-free because of ownership and all that entails. Having a physical disk is one manifestation of ownership. And with a physical disk copy, the publisher doesn't come into play - they already got their money from that copy. This assumes, of course, that the previous owner upheld their end of the deal and fully relinquished ownership by deleting the game, backups, etc. That notion is similar to DRM-free digital versions: trust in the consumer is what makes it work.
I'd still rather have the abandoned title to stay in circulation, legally but at absurd prices and risk (eBay) and illegally but with zero risk (piracy). There is no guarantee with the legal way that there will be
even copies available for sale in the future, as they can be all sold out and never resold again, whereas by piracy, there will always be a copy of a game playable.
My idea is, if the publisher doesn't really bother with the title and leave it to rot, why should we follow that? No harm keeping such games up on abandonware, and taking them down when they get back on sale.