>>407245675
>the scar with a massive scope
Too expensive. M9 is just 1500$, if map eats it, you just buy another one.
Your numbers are also wrong a bit, it's 3150/250=12.6$ per shoot. And AP chance is default.
+P is always superior on the same weapon. The only ammo type worth buying.
>In practicality though a 15 round mag will get you killed more often than not
You have 4 mags on quick access. Just aim for the head, bro.
>Pistols shouldn't be relied on as a mainline for combat.
Skill issue.
>I'm on the move so I don't attract attention
Stealth is a meme, too much time wasted if you go slowly, and if you run everything will hear you from across the map anyway. 

Main - pistol with +P (m9), "Secondary" - whatever you can find, is objectively the best price-performance wise.