The short answer is that we don’t know right now. Google is keeping information very close still as they refuse to discuss the pricing plan. No doubt that conversations are still ongoing then with publishers, developers and other partners.
It’s possible Stadia may have a subscription fee like Netflix or Xbox Game Pass however, it might be totally different. It could be similar to Steam for example where it’s free to make an account and play certain games however most will cost you $60 to purchase and some MMORPG’s will require a monthly subscription. That’s just a possibility of course. Google Stadia might even let players rent certain games for a limited time instead of buying them outright.
Getting the price right however will be tricky. Pricing will need to be fair, reasonable and attractive to gamers all at once. Especially for when the new cloud gaming platform is launched. While the idea of playing games anywhere and only needing to buy them once is very attractive, there are things that could ‘ruin’ the experience for gamers. Poor control systems and lack of support from all platforms are two good examples. While being able to play Assassin’s Creed while out is a great idea but mobile controls are not good for action or intensive gaming. We also don’t know how many platforms this will work on including consoles and Apple Macs.
It’s all a little confusing and very uncertain right now. All we know is that Google is competing with Sony’s PlayStation Now service and Microsoft’s upcoming Project xCloud which is yet to be fully announced.