I just made up my cart for both B&H and sigma4less and they were VERY close in proce.
B&H shipping was 1/3 of what sigma4less wanted. Just a heads up
He and I live in the same state, I just calculated it both ways and it's $1,749.55 through sigma4less and $1978.00 even through B&H... That's a $228.45 difference. I have dealt with sigma4less before and they are a good vendor. I love B&H and would buy through them if their prices were the same (they won't price match sigma4less, I've asked). Some people say that the warantee through sigma4less is SHORTER than if you buy the same lens through B&H, not sure how that is possible as both are Sigma EX DGs and there is no gray market as far as I know with Sigmas. They both say a 1 year warantee, but B&H says "extended 3 year USA waranty" so take that into consideration.
With sigma 4 less it takes them a little longer to get an email to you about shipping than for B&H but for us in RI the item gets here within a day from the time it leaves anyway. Everytime I've ordered from sigma4less I get the stuff in 2 days. B&H will SOMETIMES get here in a day, but only if you order very early in the day and get lucky. I don't want to say go for one over the other as they are both great. If the $230 makes a difference then go for sigma 4 less, but be aware of the waranty clause at B&H versus sigma4less.
Also the Sigma does use gelatin filters, correct. I'm also working on trying to fit the Cokin Z pro series... I really need to goto B&H or Calumet and "play" with a set of Cokins and the 12~24mm to be sure if the Zpro or Zpro will work. I'm not a huge filter person so it's not a big deal for me, but it'd be nice to be able to use a CP or ND filter as needed.