All games have “Play (Free Trial)” but there’s zero information on pricing. Is it a one-time payment for all games, for each, is it a subscription? How much does it cost?

It's a one-time payment for all games. And only one player needs to own the game in order to host and play with anyone.

Games are priced between $8-12. Once I release my third game I am going to sell my games as a bundle (similar to Jackbox Party Packs)