I know these 2 lenses are in different leagues but I am torn. I have similar alternatives already, the Olympus 40-150 and an adapted OM 50mm that takes great shots. I found 2 lenses online for a good deal, both in used but good condition. The 45mm is $200 and the 45-175 is $150. Is one of these a better value than the other that I should definitely JUMP on?