Its maybe a strange idea, but what about creating a company, buying rights of old games which can not be bought, but are not abandonware (protected by either the company or the ESA) and sell them as a cheap brand over the net?
Some gamerights must be quite cheap, because here in Hungary there is a company (
www.evm.hu) who does that and sells the games mostly for 999-1999 HUF (4-8 Euros)