Jesus. That is a terrible play and pushes devs away from the ecosystem. 2 hours only serves to hurt developers.
The problem isn't just the in money with the "it's only a buck or two for the app". You're trying to find an app you'll invest not just money, but time and your data. On iOS with this model it means you can spend 20-30$ for 5 different candidate apps and then choose one - or even find out you don't like any of them.
Now repeat this process for different types of apps that aren't multi-platform.