So here is what the bulk of my formulas look like
=IF(ISERROR(VLOOKUP($VV$4,INDIRECT("'"&$B6&"'!$d:$as"),WQ$3,FALSE)),0,(VLOOKUP($VV$4,INDIRECT("'"&$B6&"'!$d:$as"),WQ$3,FALSE)))
Again this pulling costs from other sheets which are populated and used for reporting.