I think the intended meaning is actually we give you better performance than the competition, which sells at double or more our low price of $595 (i.e., they compare the C64 favorably to other computers ranging from $899 to $1565.)
Yeah I realised once I read the comparison chart in the ad.
It's also possible that the ambiguity was intentional.. Ad copy is an art and it did compel me to read all of it to unpack the meaning. Though thinking this through I would assume that everyone interested in computers at the time would know what the prices of other products were so the $595 would immediately be understood as very cheap in comparison
