Licurg: What Interplay should do is publish more games here on GOG, not raise the prices on those already here. If Interplay publishes Blackthorne, The Lost Vikings , Atomic Bomberman , Dragon Wars and Blood and Magic next week, for 6$ each, the income from that will easily bring them a few hundred thousand dollars in the next couple of months.
Blackthorne and Lost Vikings are held by Blizzard thanks to the GBA ports. Atomic Bomberman would require a deal with Hudson. Activision published Dragon Wars, so likely the rights are with them. Blood and Magic is a D&D game, so it's not happening thanks to Hasbro's recent license consolidation.
Legal troubles aside, those games would have to sell 75,000 copies between them to make "a few hundred thousand", which yeah, if those are the kind of sales numbers you think an obscure release gets, think again.