VHS in 2009/10?
Yep, it was cheaper and easier than buying a boxed set of DVDs.
Rest assured, I'm slowly converting my Trek library to DVD, but it's on an "as-needed" basis. At the moment, I have all the movies and TOS on DVD, but the later series are represented by a fairly random assortment of episodes on VHS, which you can still pick up pretty cheaply on-line or at this cool used bookstore in Havre de Grace.
I think the last VHS tape I picked up was that Voyager episode about the dead astronaut, which I wanted to rewatch before writing Rings of Time.
Again, it was cheaper and more efficient than buying an entire season of Voyager just to research one episode.