I have to believe that this is going to come out on Blu-ray eventually, and I think I'm going to wait for that. I've already seen the complete series and watched all the bonus stuff on the DVDs, and it's definitely one of my favorite shows, but even if I did buy this, I don't think I would start watching it again anytime soon. (I'll probably be kicking myself for this decision soon enough.)
FWIW: If you haven't watched "Six Feet Under", you probably should, especially for this price. It's a really, really great show -- funny and, for the most part, well-acted (Michael C. Hall, Richard Jenkins, Jeremy Sisto, Frances Conroy, Freddy Rodriguez... the list goes on...). There are parts about it that I didn't like (e.g., Claire's art school arc, Rachel Griffiths), but overall, it's definitely worth watching, and definitely worth $60.