So Tennessee Arms (www.tnarmsco.com) has put up pictures of their "Ghost Gun" lower.
They're saying that they should be tweaking the molds and then putting them up on the site for sale tomorrow. I believe they're saying $60 per lower.
I dig the idea of a see-thru lower.... but like most polymer lowers... I'll wait until someone else torture test it before I buy.
Pics here: http://imgur.com/a/sCbC7