Forgot to mention that the "off brand" lenses were not worth the $119 or $199 they asked for in the early 1980's when they were sold during the SLR craze. So I wouldn't think even one of those Cambron, Focal, Sears, Soligar, etc etc would NOT be worth any sum of money today.
If you must have one snag a Vivitar Series 2, or, Nikkor, Canon, Minolta, Pentax.. not sure if some of these lines had one.