No, unfortunately, this is not possible in Airtable. :frowning:
One solution for this is to create new products every time the price changes, and give each product a slightly different SKU #.
Another solution would be to copy-and-paste the price at the time of data entry into a normal number field, instead of using a lookup field. (This could be automated.)
Another solution would be to create a whole bunch of different price fields in your products table, where each price would represent a different date range. Then, lookup all of those price fields into your line items table and create a formula that picks the right price based on the date of the quote.