Here are a few I took with my Tamron 90mm f/2.8 macro. Tripod was used
ISO (I believe was) 800 f/4 1/125th sec
Same ISO (I believe, its not coming up on the Exif viewer I have) f/8 1/125th
I also tried some at f/22 to get more DOF, but even then it wasn't much more and also wasn't quite as sharp. I took these from about 3 inches away.
Got this lens from keh.com used in EX (excellent) condition for $300 with shipping. This lens new is $400. The one I got is in awesome condition. Never would have guessed it was a used copy. It takes awesome pics.
Here is one not in macro mode:
ISO 1600 f/3.2 1/80 no flash, handheld
Haven't really put it to a full test yet. But when I have used it its been fun. If price is a concern then I'd definately look at the used lenses, Sigma's 105mm f2.8 macro has gotten excellent reviews.
Another cool place to look is
http://www.pixel-peeper.com/ You can search pictures taken with a specific lens
Here are some taken with the
Sgima 105mm and here are some with the
Canon 100mm f/2.8. They at least give you an idea of what kind of images can be produced.