Anyone who owns an AR-15 should buy their binary triggers and FRT triggers now, while they still can. If you don't know what these are, you should.
There are also some pretty cool SBR-type guns out there that are not SBR's, but ordinary pistols - y'all aught to be looking at those too.
I wish I could give you a good pistol to invest in that will become more valuable years from now. Maybe the Kel Tec P50....