Shipping gets expensive when the load becomes overwide and/or over height.
Overwide is different from state to state but usually starts at 8’6”. Over height usually starts at 13’6”.
Over wide might require a pilot car, a follow car, day light only travel and even rush hour restrictions.
Over height might require extra mileage to avoid low height bridges.
So if you needed a pilot car, a follow car, could only travel during day light and it all had to travel 2000 miles through three states with various permits, well that could get expensive fast.