Well in the event of global road worker and construction material shortages (remember in the real world roads are built on location, usually by the countries workers with the countries materials, not on some assembly line half way around the globe (pre assembly roads?... batteries not included?) like the things stocked at wal-mart) that may be the cost of a road per mile. Everything construction, finance, and military based in sim country is unrealistic, so why should we have real world prices?
You can have millions employed in the army in countries smaller in population then Australia, and produce government surpluses in the trillions, if any government in real life was producing those kind of surpluses I think tax cuts would adleast be considered.