Might be country dependant, in my country they have lending and re-sale as not allowed:

(Not my photo)

Check the writing starting from the bottom left of the disc and going clockwise around the edge.

Revenue numbers without profit numbers mean nothing unfortunately. Again though, they wouldn’t sell it off at a price a single guy can afford if it was making any profit.

I love GoG, but they’re fighting realistically an un-winnable uphill battle. DRM free being their thing means that they’ll never get most games, and therefore most players.