Actually, a pair of glasses can be worth $500. When you consider the fact that they are created using proper design elements and actually shift a lot of the normal paradigms. This level of creativity and intellectual property is worth money. You pay for the fact that 2-5 years later (even less in this day and age), someone will copy it, make it out of cheaper materials and proceed to sell it at a fraction of the cost. Hiring top level designers, manufacturers and professionals generally costs a lot of money. A lot of designs aren't successful. Shipping and distribution over here isn't cheap. Labour in first world countries isn't cheap.
For major peices, I will always buy genuine - not necessarily from a retail store here though. Things are cheaper in the states or UK if you know where to look however, buying hooky products is a no go for me. I buy brand name because of quality, R&D and presence - not for poser status. If you look in my wardrobe, you can see which suits are worth dollars and which are the cheapies (of which there is only 1).
So in short, a pair of glasses can be worth $500. A watch can be worth $10k. And if we want to encourage creative minds to constantly develop new shit for our consumption, we shouldn't bicker over a few dollars.