I have been struggling with this for a month or two now, too. I have:
DA40
SMC Tak 50/1.4
Macro Tak 50/4
M 50/1.7
Macro M 50/4
A 50/1.7
A 50/1.4
Vivitar macro 55/2.8
Mamiya (m42) 58/1.7
And I know I do not need them all, but couldn't decide which way to go. I did sell my Sears 55mm/2.8 macro, so moving in the right direction. Then it hit me - buy a new lens!
So now I have ordered a FA 50/2.8 macro. If that lens is as good as most people think, I can move out my other 3 macros, and still have 1:1, f/2.8 and SMC all in one. Love it! So then I'll decide between the M and A 1.7, and the 2 1.4's, and be down to a reasonable number.