9mm factory loads are currently going for 12-14 bucks a box(sometimes less if they aren’t sold out).
40 cal is about 16bucks/box.
38special about 18bucks/box.
9mm makarov is under 10bucks/box
If you buy bulk military surplus you get much better prices. There is no such thing as military surplus 357sig or 40S&W.
357sig is one of the most expensive calibers you can buy.
see post95 for typical ammo prices.