first lens for t3i- canon 50mm 1.4 OR sigma 30mm 1.4?

[theregoesjb]

My plan is to buy the t3i body and get a decent fast 50 lens. I had pretty much decided on the canon 50mm 1.4 lens but am realizing how the cropped sensor comes into play. I am used to playing with an older minolta film camera that has a 50mm 1.4 lens, so to get something similar i would have to get a lens in the 30mm ballbark (from what i understand).

I wish i could 'un-know' this whole cropped sensor thing but it does seem to be a legitimate thing to consider. The sigma is about 100$ more and a part of me wonders if I would even care about the frame size. But I have seen online comparisons and difference is fairly big... which is making this decision difficult

I wish i could try them both out side by side and decide whether I cared, what are others opinions? Anyone own both?