This is the easiest way to get your recipe costs when you're just starting. Simply adding the cost directly to the ingredient as you go.
Updating the cost of the ingredient will ensure the cost is updated in every recipe that uses that ingredient by any unit of measure.
(Always start by creating recipes, not by Creating Ingredients)
Exit 'editing mode' into 'viewing mode' and click on the ingredient
Once you're in the Ingredient's detail page, this is where you can add a cost.
*** Add any unit of measure you like or create a custom unit based on how you buy the item. see below how - simply define the new unit from the modal
You can also get to the ingredient's detail page from the search box and the home table page.
You can also upload purchase costs via a .csv upload & via automated purchase integrations. learn more about that here