I think this adds too much friction to trying to view a website and most people, upon seeing this sort of paywalling (regardless of how much or how little is being asked) will just not go to a site that's implemented this.
It's really not meant for humans - the author here is mainly doing that for demonstrative purposes. x402 is meant for, and best for, AI agents with access to a little working capital and need to access a paywalled tool, API, or content to help solve a task.
I also think the friction is a higher obstacle than the cost.