Agreed, with a dvd burner and some good software, you can make your own backup which may even be superior to the qaulity you get from them, keep in mind they may not do a good job, do they have samples or clips so you can see what quality you are getting... I doubt it.
If you dont have a dvd burner or are not in the market for one, I suppose their service would be beneficial for you or anyone else with that situation.
To answer your question if you bought a bundle you would have to destroy whatever of that bundle you don't own an original of within 24hrs of receiving them. Thats the law in U.S. anyway but I think its also the law in just about eveyr other country too.
Hope that helps!!!