I've been doing more "panic prowling" - a number of people in my area are selling ammo at reasonable prices in allocated quantities, so I regularly canvass them and pick up a few boxes at a time to supplement my current horde.
I did make one purchase - I've been hunting for 20 round FNAR mags for months (even before Sandy Hook), and finally found some at the Nashville gun show a week or two ago. MSRP is currently around 65, someone was selling a pair for 95 each, so I grabbed one and figured the extra 30 was "availability tax". Later on I found another person selling them for 200 each.
The biggest impact on me is that I'm now overly stingy with my shooting; my inner packrat kicks in and I shoot relatively little or visit the range less often, in spite of having a decent ammo cache.
NRA Life Member