I suppose this was in another discussion I missed, but if your body is anything since (and including) the K10D or K200D, you need a couple of lenses first.
For example, my K200D with the FA135 on it is the best IQ I can get with about $600 worth of equipment (I know what you're thinking ...
how about the iPhone? ).
I consider the DFA 100 WR macro the best
overall macro you can get, and I have one. But unless you're really into macro, save your money and get one of the many different-branded variants (AF or MF) of the Cosina 100/3.5 macro.
After all, if you can afford a $500 body and $600 lens, you can afford a $1000 lens, or two or three lenses worth about $1000-1200 combined. I didn't upgrade my K-x until I'd spent at least 5-7 times the price of the body on lenses (and I bought the body when it was newly released for around $650). When I finally upgraded to a K-5 it was anti-climatic, because it hardly improved my IQ (all the IQ improvements were already coming from the lenses when on the K-x).