I think I paid the custom guy $600. Not at home to look at receipt. The floor rests on supports, simple wood blocks attached to the floor which is flat. Not necessary to mess with the contours. Hinged so I still have access to storage in the rear, as well as the battery in the front. There is some extra space above the battery too, but I never considered putting anything in there. Don't want to mess with ventilation or creating insulation on a hot battery.
2018 Kia LX HEV Metal Stream with Advanced Tech