I don’t have time to build a screenshot demo, but here’s the best verbal rundown I can offer in the meantime
Long story short: you don’t put a formula in a Single Select field. You add a formula field that reads the value in the Single Select field, and outputs the values from one of the Lookup fields based on what’s in the Single Select.
Slightly more detailed: your Single Select field contains text representing the type of price you want to apply for a given product in a given order; i.e. Retail, Wholesale 1, Wholesale 2, etc. I’ll call this field {Price Type}.
You have a {Product} link field where you link to a product from your [Products] table.
You then have lookup fields that pull in those different prices based on what product is linked; i.e. you’ll have a lookup field named {Retail} that looks up the retail price for the linked product, another one named {Wholesale 1} to pull in that price, etc. Once created, all of these fields would be hidden, and only referenced via the formula.
In your formula field (named something like {Unit Price}), you have this formula:
SWITCH(
{Price Type},
"Retail", Retail,
"Wholesale 1", {Wholesale 1},
"Wholesale 2", {Wholesale 2}
)
If you have more than three options, this would obviously be a larger formula. But in the end, your choice in the {Price Type} field would determine the correct unit price applied, which could then be multiplied by the desired quantity to get the total price for that selected product.
Does that make sense?
