Here you go
"Firearms dealers are required to process private party transfers upon request. Firearms dealers may charge a fee not to exceed $10 per firearm for conducting a private party transfer. Example:
a. For a private party transfer involving one or more handguns, the total allowable fees, including the DROS, safety, and dealer transfer fees, are not to exceed $35.00 for the first handgun and $31.00 for each additional handgun involved in the same transaction
b. For private party transfers involving one or more long guns, or a private party transfer involving one handgun, the total allowable fees, including the DROS, safety, and dealer transfer fees, are not to exceed $35.00. The dealer may charge an additional dealer-service fee of $10.00 per each additional firearm transferred.
(PC section 12072(d)) "