80g for the initial workman fee the Dwarf tells you about. After that you have to find the granite slab which costs you nothing but troops for guarding. Likewise, the armor and weapons upgrades for the troops which Wade provides costs only the ore you have to find.
"I'll stab him in the forehead with my FINGERNAIL! DIVINE RETRIBUTION!" - Egbert Aethelbald, Suikoden V