I've had my G2 for about a month now and I've decided to buy the macro and telephoto lenses. I've done some searching and the price differences on these lenses range from $70 for the pair to over $300 for the pair. What should I take into consideration when i'm buying? From what i've seen and heard the crystal lenses are better than the glass. Aside from that i know nothing, anything you guys could tell me would be helpful, thanks.