It is true that you get what you pay for. We reviewed glasses from 8 manufacturers looking at not just the lenses but just as importantly, the frames. It doesn't matter how good the lenses are if the frame doesn't hold them in place, fit comfortably and is durable enough to last several years. Our frames come with a 3 year guarantee.
As to lenses, it all comes down to the quality of the mold. Molds can be made from aluminum or steel. Steel is more than twice the cost because it takes more time to cut and it takes better quality tooling to cut. The quality of the CNC machine is most important as it has to be top grade and well maintained to hold close tolerance for cutting a smooth mold without distortion.
Likewise, the injection machines have to be top grade, well maintained and properly operated. The best manufacturers have the volume to afford the best equipment and have experienced staffs. Yes, we could have picked a cheaper source than the one we use but good quality wins in both the customer service and customer satisfaction arenas over time., every time.
The other thing you pay for is marketing. Magazine ads and complex websites cost a lot of money. Just a quarter page ad in a typical shotgun oriented publication can cost over $15,000 per year. That means you would have to take $100 of margin out of 150 sets of glasses just for that ad. You can also spend $1,000 per month maintaining a complex website. You also know that big dogs cost a lot to feed. The bigger the dog, the more it costs.
So, yes, you get what you pay for whether it's in the lenses on your nose or the logo on your case.