>3 bytes for prices up to 167772.16. If you frequently buy things more expensive than that, just have one of your servants transcribe the recipe to your favorite format.

>1 byte for the number of items. If you buy more than 255 of one thing, we'll just add another line to the recipe.

You could split prices greater than 167772.16 into chunks, delimited by using zero for the number of items in the subseqent line items.