I think it's around $50-60 (and insurance most of the time covers it) -- it's a blood titer looking for the antibodies (I think).
I have twins -- one of them got chicken pox, out of the blue, no known exposure -- just covered with chicken pox. Her twin, who shared her bed, her baths, playtime, hugs, etc etc etc NEVER GOT ANY VISIBLE SYMPTOMS. This was at 3 years old.
Last year, when they were 5, I went ahead and had the blood test run, and the doctor argued with me -- it's a shot vs. drawing blood she's still going to be stuck with a needle blah blah blah (and all the while I'm thinking -- "you're taking blood out, not putting crap in"). Anyway -- point being, the child that showed NO symptoms at all.. . not a bump, not a fever, nothing, tested that yes in fact she had had chicken pox. So she doesn't *have* to have the vaccine (Texas law requires it for school, and even though we homeschool I want my records up to date).
twinzmommy