I would like to do some nice macro shots of the rings at weddings. I was looking at the 105mm macro, and it looks very nice. The thing is the ring shot will probably be the only macro shot I take, so I'm not sure I want to spend £600 on a lens that I will only use for one shot. I'm also looking to buy the 70-200 2.8 in the next couple of weeks, so it would be painful to spend that much on the 105, which has the same aperture but just focuses a bit closer.
Are there any other practical options? Or maybe someone could suggest a bunch of great macro shots I could take at weddings to make the lens a bit more worth while.