If your defending yourself from big bro with a .22 your only hope is they die laughing at you , have you seen the armor they wear now ? Have you not seen how many people survive point blank rounds ? If your talking about plinking well there tons of ammo available up here , a quick check found Remington Thunderbolt 40gr. .22LR for 24.99 a 500 box , Yellowjacket 33gr for 10.12 a 100 box and subsonic hollow points for 7.95 a 100 box , for 9mm how about 115gr fmj for 12.99 a 50 box and that was the first place I looked so yes it's a demand problem and anyone hoarding 20k rounds of .22 has the kind of issues that probably should limit gun ownership eh !
PS for the kind of stuff most of you claim you need your guns for you should be using calibers that are cheaper to reload than buy new . I personally prefer the .338 Lapua Magnum but have been looking at adding a 7.62x51 PGW Coyote to my gun safe .