Used to have one and it is a nice gun. I sold mine for 1000 bucks many moons ago. Not sure it is collectible anymore because it uses large hole pivot pins with many PC features. With the availability of Colt and FN military classic lines that offer factory M16A4 clones, unless someone is hell bent on having a Colt AND an older M16A2 clone, it could be a tougher sell these days. The 'cloners' will most likely buy a factory A4 clones and swap the upper out for a almost true clone.