We charge $3.00 per linear foot/per side plus the cost for the Menwood finish. Fencing isn't always the easiest to sell but is a bigger pain to clean than you realize. Like Mike stated it's messy. We rip down a 4 x 8 sheet of luan into 8' x 1' wide strips and lay them adjacent to the fence. This will keep you from "washing the dirt" sort-a-speak. We base our product usage at 100 sq ft per gallon.
Fencing isn't usually as profitable as restoring decking simply for the time involved. For this reason we don't exactly hunt them down but if they come our way by all means we'll do them... at a cost.