You can find good macro lenses occasionally for really decent prices. I managed to come across one such deal and it's amazing how much nicer to use a purpose-built lens is. I'm over on the nikon side of things but i'm sure the same is true for deals on canon lenses. The tamron 90mm in canon mount has a great reputation as does the tokina 100mm
One of my first macro's after getting it. It being the Nikon 105mm 2.8 AF Macro lens.
I love how much easier it is to work with when compared to extension tubes and the like.