I'll let you know if I ever want to part with my 556xi!OK looking at my watch list on GB there are a few I'd be interested in getting
Mauser HSc pistol WWII under $400
National Postal Meter Carbine (Have Rockola, Winchester, Standard Products and IBM)
MAS 36 (for my son, I swear) around $300
Retro AR (triangle hand guards, fixed stock and carry handle)
Non-C&R a Sig 556 just dig the folding stock