Many people are only familiar with DVD special editions of films, but they were around long before the format was introduced. In the era of VHS, many films saw special edition widescreen releases, and a number of them even included extras. Although things like user-selectable subtitles and multiple audio tracks weren't available on VHS, bonus material like deleted scenes and trailers were often included after the feature, or on a second tape.
In the case of the original Star Wars trilogy, one of the series' many VHS releases included a box set of original versions of the films presented in their proper aspect ratios. Because these versions aren't yet available on DVD, many collectors still seek out this VHS box set, even though different versions of the films are available with superior audio and video quality on DVD.
As many folks start to abandon the VHS format in favor of DVD, used copies of VHS tapes are flooding the market. For people who haven't quite given up on the format yet, this is wonderful. At online auction sites for example, it's possible to bid on used VHS movies at incredibly low prices, including the original versions of the Star Wars films.
Purchasing used VHS movies online is great for the people who are looking to build up a small library of films, and when quality isn't of the utmost importance. If you're looking for movies for a child, a lot of used animated movies could be purchased online for one low price. If you have a vacation home that you visit each summer, affordable VHS movies can provide entertainment at a much more affordable cost than paying for cable or even renting DVDs during the vacation.