If anybody hasn't seen this show, do yourself a favor and do a blind buy. This show is legendary. Most people make the mistake of checking it out but cease watching because the first 2-3 episodes are for introductory purposes (pretty much character intros) and viewers wrongly assume it's going to be a "boring" show. By episode 3 or 4 the show is full tilt to the finish line with not a single weak episode. Plus, some can't keep up with the realistic dialogue (both in conversation and police department lingo) which can at times make Deadwood sound like everyday conversation.
I got season 5 for $28 on Amazon but that was with a $10 coupon for preordering Battlefield: Bad Company. Nice to finally have a complete set. It'll never be out on Blu-Ray (was only filmed in 4:3 HD), so DVD is the best we're going to get.
I repeat: if you haven't seen this, do so as soon as possible and be prepared for a lot of long nights and an occasional tardy because you couldn't get up for work.