By road you would need two trucks to haul 9,500gal - total cost $1,200. By rail you only need one rail car = $1,000
However by rail you still need to allow for transferring the pesticide from the plant to the rail yard, as well as decanting it into another tanker at the other end for local delivery, which not only involves triple handling the product (a potentially dangerous chemical) but also carries additional unspecified local transport costs.
By road, the two tankers have a total 14,000gallon capacity which is only being two-thirds utilised. The sales department should attempt to persuade the customer to up their order to 14,000gallons (2 full tankers worth) as there is no additional road freight cost, so they would effectively get a lower unit price delivered into store for that quantity.