The design for installation of avionics equipment in an aircraft is specific to that aircraft. Few if any identical airframes have the same avionics and instrument panel layouts. Older aircraft may have had previous retrofits that changed the original OEM configuration. It is not practical to quote a price for a modification without first looking at panel layouts, antenna positions, available DC power and a list of installed equipment before quoting. By giving a customer an aircraft specific quote, the potential for unexpected surprises is significantly decreased. SEA's installation quotes are guaranteed prices. SEA does not go back to the customer with additional charges if we miss something in our design review. An aircraft owner should be very suspicious of any shop that quotes and advertises one standard price for all aircraft installations. This could be a bait-and-switch tactic.