Originally posted by timo ... It's possible to waste a fantastic amount of money on what you don't really need, or what isn't really the best answer to your needs. You really have to get your head around the basic concepts and find out what your needs are in practice before you make sensible choices. I speak from personal (and expensive) experience ...
Why do you think you need to buy a 50mm 1.4? It's a great lens, but I sold mine because I rarely used it. That's my point, basically.
As a newbie who just wasted $$ purchasing (and then selling) a great lens that just didn't suit my needs, I second this advice.
I just sold a two-week old Sigma 30/1.4, after realizing the DA Ltd 35/2.8 Macro was really the lens I need. After struggling with the slowness of my DAL18-55, I knew I needed a faster lens. What I didn't realize, is that F2.8 is fast enough, and I really need close focusing, too. Both are really nice lenses, but the Sigma 30 just didn't focus close enough, and the DA35 is a great all-around lens for me. The DAL18-55 focuses pretty close, but it just isn't fast enough in many situations (for me).
I learned a lot from rushing to assume I needed an F1.4 lens, but it cost me a small bundle, too.