Function needed to select data point from range of price values

Hello, I need help finding what function I should use for a work project I am doing. We sell protection plans for the units we sell and I want to create an Excel document so that we can quickly give quotes to customers on the price of the plan. The price is dependent on two factors; the range in which the combined price of all the units fall between, and the number of units.

I want this document to allow me to input the price of a given sale and the number of units, and then populate the relevant prices of the 2, 3, and 4-year plan.

Any guidance would be greatly appreciated, it is a bit overkill to create a complicated Excel document when we have a sheet with the relevant info, but work is slow and this is what people like me do. Cheers.

Protection Plan.xlsx

Hey Sam, thanks for the response. I am no Excel expert by any stretch so didn't really know what version to put, as for my location I was hesitant to add it just in case, as this is a work account, but I'm located in Canada.

Referring to your questions;
1) I considered both. Due to my lack of experience I planned to create three separate areas; one for each of the number of units (1,2 or 3+).
2) 1 year service plan is not availible, only options are as listed, 2, 3 and 4.

Hans that is incredible mate, I appreciate your help greatly. I was clearly way over my head on this one seeing your work.