The place I work charges $375, so $400 is probably ok. Be sure to take the Superfeet back to the store that fitted you and tell them they are too narrow. The person fitting you should've checked that. Wouldn't hurt to ask if they carry wider ones of a similar nature to use until your customs arrive. (it takes us about 4 weeks to get the customs) Ask your doc how long it will take.

Feet are precious! Money spent on good shoes and the right insoles/orthotics is money well spent in my opinion!