The skillvsitemcost.2da file is the .2da file that defines the competence in lore required to identify an item and in use magic device (UMD) required to circumvent usage restrictions on an item. The UMD aspect affects whether or not such items have a red background and whether or not the item can be equipped or used; the special UMD check for scroll use—applied after using the scroll—is not based on this file (but the ability to use the scroll to get to the special check is).