here is a point that i learned from an encoding stand point.
some things are upscale, such as with anime, where they will be played on tv in 720p, but its an upscale made for that tv station, not a real 720p video.
now when you hear that, you have 2 options, get the 480p its natural resolution, and play it full screen, or get the 720p tv upscale.
the downside is that its a bigger file, but the upside is that even an upscale, the quality is better than your computer can do in real time.
my point being, is that even if these are just upscaled from dvds, the quality is still better than a dvd.and if you are like me, and only buy new if there is the option to, because some people treat there discs like crap, there is no real reason to buy the dvd version. where i live the novelty of bluray has worn off, and you are only paying a 5$ premium on brand new releases, anything a little older or not on par, you may be paying 2-5$ more than the dvd, which for the quality gain is nice at 12-15$