Another approach that uses an ITVF, only it uses the EXCEPT set operator instead:

if object_id('dbo.NotPurchased', 'if') is not null drop function dbo.NotPurchased;

go

CREATE FUNCTION dbo.NotPurchased(@UserID Nchar(10)) RETURNS TABLE WITH SCHEMABINDING

AS

RETURN (

WITH cteUnpurchased AS (

SELECT ProdID

FROM dbo.Prod_T

EXCEPT

SELECT ProdID

FROM dbo.User_Prod_T

WHERE UserID = @user-id

)

SELECT p.ProdID, p.ProdTitle, p.ProdType

FROM dbo.Prod_T p

CROSS APPLY cteUnpurchased u

WHERE p.ProdID = u.ProdID

);

go

SELECT *

FROM dbo.NotPurchased(N'001') np

ORDER BY ProdID;

You can modify it to include only products of specific types or add another parameter to limit the type. You may not be able to do it with a view because of the parameter, but you can come close with a function. Jeff has already offered the word of caution - Avoid the dreaded MTVF.