I've purchased from sfbsc.com as well and after a shipment arrived with tiny holes poked in the bags which led to salt loose in the box I called them just to let them know that the bags could have used a little packing material in the future and that I lost no more then a couple ounces at best, they sent me a brand new bag of salts. I'd ordered 20lbs O.O.
When I needed Denditric and BB would have taken too long for me to fill a last minute Christmas order, sfbsc said while they couldn't match the product price (they usually will) they -would- ship free so in the end I still paid less then BB ($ + shipping) in a crunch and instead of waiting 7-8 business days to get it I had it in 4.
If you watch the site the salts seem to rotate on which one is free shipping this week/month etc. That's when I buy. They also have so many options in size of grains that it was hard to choose sometimes.