Calculate the average sales of ""Sharp AL-1530CS Digital Copier in the east and the west superstore.
Sharp AL-1530CS Digital Copier' is the "Product Name"; average sales = AVG(Sales)
SELECT AVG(T1.Sales) FROM west_superstore AS T1 INNER JOIN people AS T2 ON T1.`Customer ID` = T2.`Customer ID` INNER JOIN product AS T3 ON T3.`Product ID` = T1.`Product ID` WHERE T3.`Product Name` = 'Sharp AL-1530CS Digital Copier'