I have also looked into this, and also found sites where there is quite a big profit margin.
However, you would probably want to find out first if you would have to pay tax by doing this. Here's what I've found so far,
If you're from the U.S:
https://bitcointalk.org/index.php?topic=352049.0If you're from the U.K:
https://bitcointalk.org/index.php?topic=331740.0If you're from anywhere else then just search for it, you're more than likely to find it here than any other BTC related forum.