Private Party Transfers are limited by law in how much it can cost. It is currently $25 for the DROS and $10 for the FFL, plus sales tax on the FFL fee, even though it is basically a labor cost. This is limited to where the buyer and seller both show up at the dealer.
There is a local gun shop (Simi Valley), Fort Courage Armory, which charges $50 for a transfer (not a PPT) (
http://www.fortcouragearmory.com/specials_Us.html).
I am also a FFL, but I just do transfers and special orders.