That is a kludgy solution - as @pagexrage said, bundling some products together and offering the group of products at a different price is extremely common. It would be very easy for e.g. a sales clerk, to forget to apply the discount.
All this "feature" does is make it easier to add some items quickly to estimates, invoices, etc. Not terribly useful, IMO. I already have hundreds and hundreds of items - I don't want to pollute my products list with even more entries that don't really add value.
