After much deliberation I recently bought a Sigma 18-125 OS. I was upgrading from my 18-55 IS and was debating between the 18-125 and a used 17-50 non VR. I ended up choosing the 18-125 because of its range and OS (which would hopefully give me similar low light capabilities to the 17-50 as long as my subject wasn't moving). If I had gone with the 17-50 I would still have nothing in the telephoto range and would probably have to buy a 55-250 to go with it, so I figured I was saving some money too. I currently have a 50mm 1.8 and I am planning to also get a 85mm 1.8 soon and a 30mm 1.4 when I can afford it. This way I have a set of primes they will do much better in low light than the 2.8 on the 17-50 and I also have a good travel zoom. Does this seem like a good plan to you guys? I can still return the 18-125, but I recently went to Spain and enjoyed shooting with it (although I did wish it was faster sometimes...). Am I being stupid keeping the slow and less sharp 18-125? What do you think of 30mm 1.4, 50mm 1.8, 85mm 1.8, and the Sigma 18-125 as a kit?