I just got tickets through Hobbit Travel. I checked out the website first (
www.hobbittravel.com) and then I called and worked with them. They were VERY helpful as we tried several scenarios since one is traveling from Portland, OR and two of us are coming from Milwaukee. We paid $597 from Milwaukee and I think the PDX person paid low $700s for a late Feb-early March trip. We're flying on Continental and have only one layover in Houston.
According to their website, from San Fran you would start at $510.
I've had a very good experience thus far and based on that, recommend them.
Gidget