I was thinking about picking one of these up from Costco local... $640 in the store..

 

http://www.costco.com/Browse/Product.aspx?prodid=11660547&hierPath=93*1924*88355*&whse=BC&topnav=&Browse=&lang=en-US

i feel weird buying a mattress I could not try out.  Do they only make this model for Costco or could I find it somewhere else?

Any feed back on these Posturepedic sets?

I had a Posturpedic set for 15 years and it held up very well, but I understand quality has degraded over the years. The one you linked looks very nice, but personally I wouldn't buy a bed I couldn't try out first. Finding this mattress to try at another store will be very hard since each retailer sells it under a different name.

If you do order it, just make sure there's a good return policy, which I believe Costco does have, and no unforseen fees.