I've noticed that with glass you can generally see the jump in price in the performance, i.e. I can't see a law of diminishing returns. Well for traditional looking scopes. I guess if you jewel encrust it and add bling, then yeah. But the first noticeable jump is when I have gone to scopes like Leupold and that was an eye opening jump over what I used previously. Having used Swaros, I notice quite a bit of improved performance over my older scopes, including the mid-level ones.