Josh,
It would really be hard to say. The foam for the bluffs was free out of a dumpster, the bark for rocks were free, the LP tank was $8, the oil plant is pieces of an old Walthers kit left over fron a old layout. and the scratchbuilt shed is made from scraps of wood and corragated siding. I can't give you a definate answer. for me it is priceless!!
