You can see answers all over the place here. I guess some people are VERY optimistically estimating how low they may be able to find gun prices, others may be basing it off prices from years ago, while some areas may have VERY low gun prices. Based upon local and recent prices (within the past year, not the past few weeks with panic buying), I don't think I could buy 1/2 of what people have put on this list with an under $400 limit. Though, at least 1/2 do seem to be realistic choices (and many are very good choices).
Strictly keeping by the set limits, I'd be looking at:
- Bersa Thunder .380. The size and caliber aren't ideal, but they work. They are a little big for a small .380 carry gun, but it works (and can work well) in all except the most discrete carry situations, but is big enough to run a couple boxes of ammo through it at the range without too much discomfort. The caliber isn't ideal for defense, but is workable, it is a little expensive for a lot of range practice, but isn't too bad.
- The new Taurus 856 Defender. J-frame sized, 3" barrel, 6 round .38spl. Get it in steel and not aluminum and it would be OK at the range (especially with a full grip), though their website lists it up to 35oz (no way it is that heavy) it would also work CCW. The cheapest runs at a $425MSRP, and the most expensive at $477 (all with night sights), so they'd likely all run at or under $400 at the store (maybe the most expensive would be out of the price range).
- S&W M&P40c. Around here you should be able to get a 1st gen for under the $400 limit, good luck finding a M2 anywhere near that. My 1st gen M$P40c is comfortable at the range, and when in a carry state, I can conceal it well and it is comfortable to carry.
- S&W SD40VE. Inexpensive, proven, reliable, reasonably accurate, a good intermediate size for both CCW and the range.
- USED Taurus 65 or 66 (preference to the 7-shot 66 over the 6-shot 66). There is no way anyone is getting either for under $400 around here new, but used that may be possible (though one is more likely to find the 6-shot 65 at that price). Medium frame, 4" revolver, would be possible to CCW, though not ideal. It would be a great HD and range gun.
- Used RIA 1911. It might be possible to get for under $400 in decent shape in most areas of the U.S. An Officer sized or Commander sized gun would carry well, even if all steel, and a Commander sized lightweight aluminum gun (likely not to be found under $400 though) would still be comfortable at the range.
I think my first choice on the above list is the M&P40c, but all would be strong contenders.
Now, a more realistic scenario, and less arbitrary, should the current situation lead to enough of a personal economic/financial catastrophe that I need to sell everything off, but want to keep one, which would I go with. It likely wouldn't be a gun that sold for less than $400, though I wouldn't keep one of my more expensive guns since they'd bring me more money (that I'd probably desperately need at that point). The S&W M&P is still high on that list, but so is my Officer sized RIA 1911, my CZ 75B Compact, my .40S&W SIG P229 (bought used and only in fair condition cosmetically for $499), my S&W 65LS (though it is worth enough that in such dire financial straits it may have to go), and my CZ PCR. There is a slim chance that I'd go with my Taurus 85CH, not ideal at the range (but doable since it is all steel), I'd hate to only have 5 rounds, but it isn't worth much (so I wouldn't get much for selling it) and it is 100% reliable. If I had to choose right now and not spend time thinking about it, it may be the 65LS only because it will be the hardest to replace later (appreciation and increasing scarcity). If I had to grab one that would most likely come with me if I had to leave my home right now (and thus abandon and not sell my other guns), that would be my CZ PCR, P01 or 75B Compact. Due to lower cost ammo (an important criteria if I was in such bad financial shape), one of the 9mms may win out from that angle as well (thus if I kept my M&P40c, I may try to trade it on a 9mm version).