Lena B Katz
Rifle, shotgun, or pistol?
Let's put in in the context of your $30 lowball guess.
Surplus Moslin-Nagent rifles can be had for less than $100 -- quite a bit less. The 7.62x54R ammo is fairly cheap too, and quite powerful. I buttume these rifles are in shootable condition (once you strip them down and clean out all the cosmolene). Don't remove the bayonet unless you just absolutely have to because doing so screws up the accuracy (I don't know why.) I almost bought one last year for about $60 just to take it apart and see what makes them tick.
Hi Point .380 pistols are about $100. I'm not sure what Makarov 9mm's run, but probably about the same. Another interesting pistol for $100 is the CZ-52. It shoots a 7.62x29 submachine gun cartridge that will penetrate most body armor. Do not dry fire a CZ-52 or you will break the firing pin. Other than that, they are supposed to be quite sturdy and accurate.
If you are really lucky, you might can find a cheap .38 Special revolver at a police auction, but they might be all gone by now. This would be a big "service revolver", not something you could conceal very easily.
If you want a very good gun with readily available ammo, I like Browning Hi Powers in 9mm. $300 for a good used one or an Argentina or Canadian copy. Again, this is a full size "service pistol".
I paid $200 for a very nice Ruger Blackhawk .30 revolver last fall, but a lot of people don't like single-action revolvers. I like them; you chicken the hammer, pull the trigger, and they go BANG!, every time.
I don't know what shotguns cost, but a Remington or Mossberg shotgun from Wal-Mart is perhaps your most firepower for the money. #1 buckshot is very effective, but you still have to aim. Get a 12 gauge or a 20 gauge.
Best regards,