I guarantee you that NIB one will go for far more than $40. I predict it'll go up to at least $100.
There were just three NIB Model M's that sold for $30 each, BIN. Ok, that was a bit unusual to see them go for that low, but $100 IMHO is too high. The $60 to $85 range seems more realistic to me. But of course if you get two or more people who really want it, the price can go well above the normal range.