Well right up until and sometimes after the shooting, you could get perfectly serviceable AR's at Walmart for very reasonable prices.
I went to the gunshow in Kansas City yesterday. AR's and like guns were literally through the roof. $3000-4000. I did not see one reasonably priced. The closest thing was an SKS for $600-700. The price on it was probably double, but since they were relatively cheap beforehand, it doesn't seem that bad at this point.
I saw NO thirty round clips. One vendor had a decent supply of twenty rounders for $24.95 apiece. That doesn't seem too terribly bad to me, given the situation. Ammo was available, but I don't know what the prices were. High capacity pistols seemed abundant but I can't speak to the magazine situation with them.
Most of the assault rifles that were left were sub-par, at least in appearance. I've bought such guns before and they were fine after a cleanup, but they weren't cherried out guns for the most part. I did see two very pretty AR's. I don't know what brand they were but I saw the same ones, I think, at Tulsa a few weeks back. They were about doubled in price at $3000, IIRC.
The parts situation wasn't dire, but they looked somewhat sparse. The ones I priced though, were a lot less spendy than the guns themselves. I bought a set of cheap BUIS' for $65 and that's as cheap as you'd have gotten them for awhile now.
