AR-15 Retractable Stocks

Recently on Facebook I saw a picture of a Remington 870 with a retractable stock, which was completely badass.  (There is a difference between retractable and collapsible.)  I then set out to find it, but didn't see anything for an 870.  It turns out that the picture was using an AR-15 stock adapter and a Nordic Components CRS (Compact Retractable Stock).  Midway used to have them for $120, but they're now discontinued.  There was a similar one made by Loki Weapons Systems, but they ran afoul of the ATF and are now defunct.

The only similar item I could find is the North Eastern Arms CCS (Compact Carbine Stock) over at Brownells.  This isn't the same since it actually has a buffer tube, whereas the CRS only worked with buffer-less systems (such as the 870).  Further, it includes a modified bolt carrier group and such, and so costs $330.  Ow.