1) Find several licensed dealers near you. Search the yellow pages, you'll find a bunch between pawn brokers and guns
2) Call each one and ask "how much do you charge PER gun for an FFL transfer?" If they don't know what that is, hang up.
3) SHOP AROUND...no such thing as "the going rate around here". In my town I've been quoted as high as $65.00 and as low as $15.00 per gun. Some dealers do bundle deals. There is nothing special about a transfer, so other than being honest, service doesn't really play in here, although I would encourage you to support your local dealer when you find a good one.
4) Once you find one and agree on the price for what you are transferring (be sure to tell them what kind of gun or receiver it is when getting a quote) either ask them to send a signed copy of their FFL to the place you will be buying from or drive by and get a copy or drive by and give them a stamped envelope. Some dealers have preferences as to how to handle it.
5) Once the seller has a signed copy of your FFL Dealer paperwork, you will place your order and pay the seller (not your FFL dealer) for your item.
6) Seller will ship item to your FFL
7) FFL Dealer will transfer the gun to you (after you pay them their transfer fee) in accordance with your local laws.