Try

;with

T as (

SELECT VendorCode, 1 as Seq, UnitPrice, Qty, (UnitPrice * Qty) as Total

from Sales

union

SELECT VendorCode, 2, sum(UnitPrice), sum(Qty), sum(UnitPrice * Qty)

from Sales

group by VendorCode

)

SELECT case when Seq=1 then VendorCode else 'subtotal' end as VendorCode,

UnitPrice, Qty, Total

from T

order by T.VendorCode, Seq;