I am also weighing my options for a Macro lens, but I needed a point and shoot more than anything and spent my money on a Sony RX100 which I got today. Fantastic little camera with a huge sensor 1.8!
Anyway, while looking at my options, I ran across the typical lenses by Sigma and Tokina which offer a MACRO mode. The prices of these lenes were in the $170-$199 range. Although, it is not a true macro lens, it does have a macro mode and if you do not already have a zoom, this may be something you are looking for. They are not fast lenses though.
Ideally, when I do buy, I plan to get the 105DC.. or something FX, I have an D7000 but half my glass are FX lenses. I anticipate moving to Full Frame soon. The reach on my FX 24-300mm on my D7000 Crop is insane.
Nikon Pimp #82