I've found this deal on Craigslist.
Quote from seller:
Here I am selling my like new Sigma 30mm f 1.4 EX DC HSM with 3 filters. A UV filter, a circular polorizer filter, and a 1.8 neutral density x64 filter (6-stops). All B+W brand. From the pictures my nd filter doesn't look like that. I need to use my lens marker to rid my fingerprints. You can't beat this price. I'm selling because i'm trying to purchase another lens. Email for questions
You can read more about the lens and filters here
I think I'm gonna jump into the deal?
Edit: Price is $400.