They were a good value way to pick up the movies definitely. I don't know about the tv shows though., Even though the TNG season boxsets retailed here in Australia for $140 a pop or some such stupid number at the time for only six discs, collecting 10+ issues of the magazine in order to get a full season would probably work out more expensive. Darned if I can remember what the mag/disc combo originally retailed for.
I can imagine that on some level the DVDs on those magazines, in their individual collectable cases, would have a collective collector's value that is much higher now than the bog standard boxsets that everybody and their dog bought at the time, though. And that value will skyrocket in the future, especially for a complete set.