I'm getting ready to buy a Pentax K10D from B&H. I've been reading reviews and stuff on here. I'm going to get the kit lens with it, an 18-250 f/3.5-6.3 zoom lens, a 50mm f/1.4 prime, and the battery grip. I am also very interested in macro photography. Insects mainly. I'd like a macro lens in the 100mm range. I'm looking at these two... This one is the Pentax 100mm f/2.8. It's about $125 more than the Sigma. http://www.bhphotovideo.com/bnh/controller/home?O=cart&A=details&Q=&sku=351697&is=USA This is the Sigma 105mm f2.8. It's cheaper and I can't tell any difference between this lens and the Pentax lens. http://www.bhphotovideo.com/bnh/controller/home?O=cart&A=details&Q=&sku=351697&is=USA I'm leaning towards the Sigma. I've had a couple of film SLR's before, but never had a Sigma lens. Is the Pentax lens worth the extra cash, or should I just go with the Sigma? Do you guys think that all of these lenses are too much to take on for a noob? I've taken a photography class before and am familiar with SLR's. I can afford it so that's not a problem. Thanks for any input!