No. They're half the cost because they don't spend half their money paying for a central bureaucracy. They spend almost all their money on buildings and teachers.

I’ve seen religious schools accommodate some kids with certain disabilities, to the limited extent that they are able. Kids with serious disabilities will also often get supplemental special education provided by the public school system.

As for poor kids, the religious schools that I know about are priced lower than actual cost and they rely on donations to make up the difference. Scholarships are also available for really poor kids.

Where I live (California) there are no public vouchers or other public money for tuition at private schools.