They are expensive, like $7,500 for the California King size. Probably worth it, though.
I think the one she got at Overstock was 1498.00 or something like that, queen size. Not a bad price, she has had it couple years and still likes it.
just went to sight to check, do not have what she bought now, only show mattress toppers or top mattress. She bought the set, a good name brand set.