Buyers market = people can buy games o plenty, priced affordable. Buyers markets generally mean prices are dropping. In this climate, sellers can't get what they want price wise, because they can't find a buyer. Or the seller loses significant money when they sell
Sellers Market = sellers can ask what they want, new games are selling like hot cakes, and people start asking outrageous prices because people will pay it. New companies make money hand over fist because there is plenty of profit. In this climate buyers are searching for games, can't find them and are willing to pay a premium. In this case sellers typically lose nothing (very little), or profit.
I personally think it's a mix, but for the most part it's a sellers market. If a guy has a shipping container with fifty 90's Williams games in it he is in a very good spot. In a buyers market....he would just be trying to get rid of them. Like a shipping container full of 90's arcade games.
Arcade games are a buyers market, people don't want your old broken T2 arcade game and you would be lucky to get $100.... Heck I ended up giving away the last of my "project" arcade games.