I've had a Blu-ray player for a little over 3 years now, and while I generally buy new/missing titles on Blu-ray, I haven't gone for mass replacements the way I did when I transitioned from VHS to DVD. The ones I have upgraded are titles I really love -- some Disney films as they come out of the Vault, Firefly and Serenity, the LOTR trilogy, the James Bond and Harry Potter films, 2001: A Space Odyssey, Buckaroo Banzai, Star Trek II: The Wrath of Khan. And I'll certainly think about upgrading if a film is getting a reissue from Criterion, Arrow, or Shout Factory. It's way too expensive to upgrade every time a new format comes out, so my advice is to pick and choose what you really, really want in HD. A lot of the British TV has higher list prices. Each complete season of the revived Doctor Who usually has a list price of $80 on DVD, and they haven't come down. Ever. In 14 years. Perhaps in recognition of this, the BBC recently put out less expensive box sets (one for Eccleston/Tennant, one for Smith, one for Capaldi; not sure what special features they might or might not include from the original sets), but haven't withdrawn the old complete season sets.