Speaking of this show... I can't find all seasons of this on DVD/Bluray anywhere. Seasons 1 and 2 can be found if you have the money, but seasons 3 and 4 are n

Speaking of this show... I can't find all seasons of this on DVD/Bluray anywhere. Seasons 1 and 2 can be found if you have the money, but seasons 3 and 4 are nowhere to be found. I loved this show and would like to own physical copies of it, but they just don't seem to exist anywhere.