Hi, I want to acquire a macro lens for my A100. I've tried the Minolta 100mm f2.8 D and I find it absolutely great. The problem is that new (or the Sony replacement) is a bit too expensive for me at this time. I've tried to get a used one but they are scarce. As an alternative, I've read very good things on the Sigma 105mm f2.8 EX DG. It's much more affordable (even new). Anyone has experience with one or both? Should I go for the Sigma or wait for a used Minolta? Thanks for any input.