Let's not forget that and 2nd hand market pricing influences will be region-specific. Most of the big mining operations are in China, Russia, Iceland, the US or various 'Stans'. I don't think in Australia or where I am in Western Europe we'll suddenly see a flood of 2nd hand cards that are accessible to gamers. Sure, you can always fleabay internationally - but that makes many people pretty nervous and rightfully so - the scammers will be hard at work looking to fleece people who think they have found a "great deal on a used mining card". I definitely thing hobbyist miners will start to sell cards in the lead up to and after the merge, but it won't be enough to saturate the market and with new GPU prices likely to remain astronomically high there will be no reason for people to take slash their second-hand pricing. Just my 2c.