If you buy powder in 4# or 8# bulk you can get it for less than $20 per pound, down to maybe $15 per pound if you buy 8#. Primers are I think about $3 per 100 in the stores, but if you buy say 1k or 5k at a time online you can get that down to about $23 per 1000 at some online places.
45, 357, 9mm, 40 - all about $4.50 per 100 (assuming 5 grains powder per round at $20 per pound = 1.5 cents per round, and 3 cents per primer). That's casting my own boolits which I don't count as any cost. Call it maybe another half cent per round which is probably too high for the bullet lube and the electricity to keep my melting pot going.
Buying bullets for these, I have seen the cost of cast and plated and jacketed bullets jump way up in the last year. 2-3 years ago I remember you could get cast bullets for about 3 cents each and jacketed pistol bullets for about a nickel each. For heavy bullets like 230LRNs even the cast bullets are over a dime now, and the jacketed ones are up around 20 cents each I think. Jacketed 9mm/357 bullets are more like 10-15 cents each IIRC. This is just a gross average price from me looking around the internet, if you find better prices though I'd jump on it before it goes away.
223 - that hurts a little more because I don't cast for that. Powder and primer comes out to about 10.5 cents each and the cheapest bullets I can find are 55FMJs for about 8 cents each shipped, so say 18-19 cents each.
I do cast for 8mm Mauser, and 7.62x39 and 7.62x54R. Not sure why I do it but the per round cost is only powder and primer, say 8 cents each. In order for the cast bullets to spin stabilize I don't load them any hotter than about 1500 fps, so that's what I meant about not sure why I do it. It's fun for plinking and I guess up close those would be ok for hunting or even self-defense, but not past 100 yards probably. 30 cal bullets (308, 312, and 323) in the 150 grain range are around 20-50 cents each depending. Through searching the internet I've found some places that sell pulled milsurp bullets for less than that. However they're all sold out now
so I haven't had a chance to make good on that. Cole Distributing has good prices on 308 softpoint bullets so for my 308 reloading I've bought a bunch of those to hold me over.
There is some capital cost to casting, for me I've spent probably $300-$400 over the last year. Bought about 10 different bullet moulds at $20 each (gotta love that inexpensive Lee stuff). Bought a melting pot, lead thermometer and hardness tester (those last two are luxuries for casting that you don't really need, and together they were about $80). If you just can't find any scrap lead, you can usually buy some from a tire store if you look around. I get most of my lead for free, mostly as scrap lead shielding from a hospital and some from a scavenger friend of my dad's who never throws anything away. He's gotten me lead bricks from somewhere, cans of old lead fishing sinkers, and other wierd stuff I don't know where he got it. I called 10 local tire stores and only had one of those let me buy a half-bucket of dirty, nasty wheel weights for $20. If you can make halfway friends with the tire store guys, you'll probably have better luck giving the guy a six pack to just slip you a bucket of WW now and then.
