As EASYG stated so well, one gun correctly used will yield many more if need be.
After a certain point stocking up becomes ridiculous. Now, if you admit you are just buying more guns because you like them, that's your decision and it's great.
One good long gun, one good carry/home defense and 100 rounds should enable you for any situation. If you used a weapon defending your property from a group/crowd/whatever, should you survive, just take the weapon that was to be used against you and it's yours.
Last night here in West Palm Beach 3 animals (badguys) went into D&D with shotgun and two pistols. Shot 3 elderly customers in face with shotgun. To be honest I would have been glad I had my 340PD on me but definitely would have felt undergunned. My Glock while not a shotgun, would have given me more distance and higher round count til the cavalry arrived. Sorry for the extra rant, just angry about that incident.
As of now I believe all 3 victims are still in intensive care, one literally had his face shot off, and most of his wife's also. The 3 animals got away and went onto rob two more stores that night, no shots though.
Be safe to all, and be aware of your surroundings.