The first SQL is:

SELECT i.item_code, i.description, c.description, count(*)>1 as kit
            FROM
            0_item_codes i
            LEFT JOIN
            0_stock_category c
            ON i.category_id=c.category_id GROUP BY i.item_code ORDER BY c.description,i.item_code

And it ends up including foreign item codes in the list as well, which can't have prices

as a check I tried to enter a Sales Order and noticed the Foreign item codes were replaced with the proper stock_id

tom