I'm thinking about selling off some of my gun and knife collection to fund a registered M16A2.  What's the going rate for a new/like new pre-86 M16A2 receiver these days?

Add - the last time I checked they were around $15K, but that was years ago.

This chart was last updated December 2014...
 

That is very informative, thanks!

That spike since Jan 2009

Looks like it mirrors the stock market...

 

$15k??




But seriously, add $20k to that and then you're in the ballpark for a brand new one in the box

Just a rough price guide for the M16 market...
RLL $12-15k
RR AR15 Auto Conversion $15-18k
RR Colt M16A1 $20-26k
RDIAS $22-28k
RR Colt M16A2 $27-33k

If you're in the market for a MG or just want to do some day dreaming here are some places to watch for good deals...
http://www.sturmgewehr.com
http://www.shootersdepot.com
http://www.atfmachinegun.com
http://www.autoweapons.com
http://www.impactguns.com
http://www.subguns.com
http://www.onlythebestfirearms.com
http://www.davidspiwak.com
http://dealernfa.com
http://www.gunbroker.com
http://www.nfasales.com
http://www.classiiidealers.com/
http://www.machinegunpriceguide.com/

M16A2s have not been $15k for probably over a decade, but on the bright side you can get a AR15 conversion RR such as a Olympic Arms for around that price. It may not be as glamorous but it gets the job done and anyone standing more than 5ft away wont be able to tell the difference.