I would really appreciate some support to come up with the correct formula for the columns in the screenshot below.

I want the price in the standard pricing column to auto-populate when a selection has been made in the payment options column.

For example, suppose I select 10 instalments in the payment options column. In that case, I want the standard pricing column to automatically associate $150 with this option and then automatically add the $150 to the standard pricing column.

The same, for example, with the option paid in full, should automatically add $1500 in the standard pricing column.

Assuming that the total is always 1500, your formula would be pretty simple using SWITCH() and some math. Convert your {Standard Pricing} column into a formula using:

^ in plain English, the formula is saying “if Payment Option is 10-installments divide 1500 by 10, if its 3-installments divide by 3, if its paid in full divide by 1”