In Charleston, we also make copies at no charge whenever asked.  I feel
that the people pay their taxes and that's enough.  As far as giving them
an extra copy when you initially mail the bill, they would just lose it.
We used to send 3 copies to the taxpayer, but don't anymore.  Yes, it's a
nuisance, but I consider it part of the job.  It will end soon. (well,
mostly so)
We DO charge when we have to FAX a copy to a long-distance number ($1.00)