What is your opinion on this mattress?  It seems to have a little thinner springs than what I've read on here.  But my main question is I think they are trying to pass this off as a latex bed and I only see 1.57" of latex.  I'm not yet familiar with the other HD foam and the Marvelux foam.

http://www1.macys.com/catalog/product/index.ognc?ID=420851&PseudoCat=se-xx-xx-xx.esn_results

Is this worth $500 or is it something I'd be having remorse over in a short time?

$500 maybe but not $5000 listed on their web site....not sure you meant $500.  It looks like a hodge podge of things to hope that marketing folks can make everything sound complicated and special.  Have you laid on it?  Why are you focused on this one?  I'd be suspicious of all that hocus pocus in the description.  My guess is you will regret it after 3-12 months.  I've found memory foam doesn't provide much support and poly foam breaks down. 

It is a used mattress from some small old person - 5'2" 135.  They are getting some mechanical bed and they put this on craigslist - It's less than 1 year old.  I was skeptical to begin with, and I don't care if its free - if it wont last I don't really want it.