Manila to Shanghai - Shanghai to USA

There's no fee.

But he has no guarantee to get a temporary entry permit to leave the airport.
It's up to the immigration especially as it's a day transit and he doesn't stay overnight in a hotel.

Okay! So without a hotel booking it’s unlikely he gets a visa to leave? What if he books a day tour? Is there anything he can do so he can be sure to leave the airport. What is the chance they let him through? Is it like a 99% chance they will allow him through that it’s more common they allow it or more chance not?

It's not a visa, it's a temporary entry permit (that's something totally different).
Nobody can give you a proper answer as it's up to the immigration.
The chance is 50/50 to get one.
At the moment it seems that Shanghai immigration don't give a permit when the transit is under 12 hours, so he's at the borderline.
But it can chance the next day without warning.
As i said before, there's no guarantee to get a permit when yo utravel on a 24h twov, it's always up to the immigration.

The only way to guarantee is to apply for visa from Chinese consulate in the USA prior to the trip. US passport can get 10 year multiple entry from the same price as a single entry tourist visa. Its $140 + and fees should you go through a visa service vs in person application.