The cost will very depending on where you get your prints done, and the loacality of the place of business.
I had to get a cert of eligability, two sets of printsand a hundred bucks. I had to file with the feds 2 sets a passport photo and two hundred bucks. I had to get a business license 30 bucks, a resale license, free. I had to get a city firearms licence 300 bucks. To get all these licenses I had to have a comercial address 1500 bucks a month and utilities and such. Had to have adequit security including bars and alarms, safes, etc, more bucks. Once all this is done and youve had fed interviews and city inspections and get all the paper licenses then you can send another hundred 25 bucks to the state of CA to get a CFD #. If you want to buy and sell used guns your going to need a second hand dealers license, another 3-4 hundred bucks after all the prints and passport photos...
Dont forget insurance.
After all that, If the feds or anyone alse decides your only in it to enhance your personal colection, theyll pull your license.
Oh I forgot, I had to get an HSC instructors certificate..`
Now that I've done all this I've also signed over my right to privacy in my papers and effects. I have to allow the governing bodies access to my inventory and reecords upon request during my normal business hours. I also have to trace any firearms sold through our shop withing 24 hours of the request.
Having been this far through it I would not have done it just to beef up my collection.