If there is value in one column then a $ generates in another

Hi there,

I am trying to create an excel formular where in Column G I have a drop down menu with either Long Hire or Single Hire as the options. When someone selects the Long Hire in Column G I want it to populate with a rate in column H and when they select Single Hire I want it to populate with a different rate in column H.

Single Hire 40
Long Hire 120

Does anyone know the best way for me to achieve this please?

Cheers,
Jess