Is this what you are trying to do!!!
SELECT its.storeid,OnHandQty,(OnHandQty*rv.price) rtvalue,rv.price,its.itemid,(mcl.descr)subcat,(its.descr)itemdescr,mcl.parentclass
FROM StoreItem its
JOIN
(
Select A.itemid , A.Price , A.effectiveDate as currdate
FROM EffectiveStoreItemRetailValue A...