construction estimating

I am trying to build a sheet within a book that includes several dropdowns allowing users to select an item of equipment with varing sizes, based on size selected insert the proper amount in a column for install cost and in another column connection cost.
B1 C1 D1
A1 Dropdown install connect
Chiller 40 to 300 tons $ $
300 to 750 tons $ $
750 to 1200 tons $ $

My choice would be to have the dropdowns hide after selection is made and $ amounts remain in C1 D1

Thanks