I remember watching this show on PBS in the late '70s / early 80s. It is without doubt one of the most fascinating, educational, entertaining shows ever put on TV (I rank it with Carl Sagan's Cosmos).
I have volumes #1 - #4 on VHS; It was pure luck that I saw Steve Allen's office address in a magazine in the 80s. I wrote to him and his assistant responded with an order form for the tapes. Although approx. $15 / tape, I could only afford those 4 volumes (I often kick myself for not grabbing the entire series).
I certainly will vote on the website to request they be released on DVD. They should be required viewing in all high schools / colleges. What a shame that shows of this caliber are so rare.