I use a Pentax 100mm macro (yes, yes, I know - I'm the only one with a Pentax digital SLR
), also purchased at B&H photo. Fantastic lens.
You can actually do far better on lens price online than you can even at B&H. If you're not in any hurry, you can go to B&H, try out the lenses, find the one you love, then shop around online a bit to see if you can get an even better price on it. I got my wide-angle lens from photoalley.com $150 cheaper than B&H had it for. (Conversely, I was never able to do any better than B&H on my 28-200mm lens).
I'll probably be the only one to give you this advice, and it will likely fall on deaf ears, but I'm going to ahead and give it anyway. If you are new to the photography hobby (which I suspect you are considering all of the questions you are asking about a macro lens), I recommend you invest in something like a 28-200mm lens. They are extremely versatile, you don't need a tripod, light enough to carry with you everywhere ... it's my "I don't want to carry my camera bag and four lenses around" lens. And it does a fair job for macro photographs - I've actually gotten many of my best tank photographs with that lense as opposed to my macro lens. It is less expensive and you will get far more bang for your buck. If you end up sticking with photography, then later on your can drop the $500+ dollars on a macro lens.
This photo was taken with a 28-200mm lens, stopped all the way down:
Could I have taken the same photo with my macro lens? Absolutely. Could I have gotten EVEN CLOSER? Sure. Did I need to in order to get a good pic? Nope.
Just my $0.02.