I saw some autographed photos of the stars of this show for sale they range in price from $30 to $170 but Guy Williams who plays Professor Robinson his autograph is worth $3,000. Mainly due it says he left the show when it was cancelled and went to Argentina and was never seen in the USA again, apart from him appearing on Family Feud in 1983, he died in Argentina in 1989 aged 65.
Guy Williams could have had an even better career. He had been offered up the role as Ben Cartwright in Bonanza but turned it down.
They did a new Lost In Space movie. Funny there never was any sequels.