Amazon has the 3 season box set for
$55 on sale (link).
I borrowed the first season from a friend and thought it was great. Very unique, and one of the few shows I genuinely laughed aloud at.
I don't buy DVDs, but ideally will be able to watch the second season in the not too distant future. I rarely watch sitcoms, or TV aside from sports, but shows on DVD are neat, as they allow one to weed out the quality and watch the shows straight through.