SHTF looting scenario - probably
Going from a fully controlled situation with choice (i.e., looking at my safe) to the generalized random normal day, absolutely not.
But an uncontrolled SHTF scenario - think Kyle Reese in Terminator or the kids looting a parent's store in Red Dawn.
If I needed a weapon and had to choose among an untested new firearm or an untested used firearm, the new status would be compelling on an apples to apples basis. Apples to oranges, maybe not.
If faced with having to arm myself during the process of looting a gun store for SHTF survival, I'd loot in the following order:
EBR, shotgun - pump only, bolt-rifle in a common chambering
new Sig, because that's what I'm familiar with
new HK, new Glock (full or compact frames only)
used good/clean looking Sig (again, due to familiarity)
new Beretta, new Ruger, new S&W semi-auto, etc.
any new S&W or Colt revolver (I'm not familiar with revolvers) in .357m/.38sp
used full or medium frame Glocks
used HK, used Beretta, used S&W auto
used S&W or Colt revolver in .357 or lighter
any 1911 (I'm unfamiliar with the design)
any revolver in .44mag or heavier
single action .22lr semi-autos or .22lr revolvers
Browning HiPowers or other single-action semi-autos (like 1911, unfamiliar)
Kahrs. dunno how to take those apart.
new or used sub-compact frame Glocks
Now you're hitting the bottom of the barrel. .380acp/.32acp/.25acp stuff, then:
questionable looking beater used Sig
Desert Eagle, new or used
any other used semi-auto other than Raven/Jennings/Lorcin
derringers
Louisville Slugger
Raven/Jennings/Lorcin, any condition