Not to beat a dead horse, but asking about the cost of handloading .223 is similar to asking what a car costs. Well which car are we talking about ? What options does it have ? Etc.
For example, if you just happen to pick up a few hundred .223 cases lying on the ground at a range, then the brass is free. You might shoot with a buddy that doesn't handload and he offers you the brass. You might also buy mil-surp brass and in the interest of saving money be willing to remove the crimped primer pockets. Or you might want only the best and buy Lupua brass.
You might buy surplus powder. I got a smoking deal one time on 65 pounds of powder from a guy that was an FFL, went out of business and got tired of all this stuff sitting in his garage. I bought everything he had including the powder, 16,000 primers and all kinds of other stuff for like $200.
Bullets are one of the most expensive components. Do you want premium hunting or varmint bullets ? Do you want precision match bullets ? Or will pulled millitary bullets suffice for the type of shooting you do ? I personally buy bullets in bulk from Midway, either Winchester or Remington.
Then of course, the cost of all components depends on the quantity you are buying. Are you buying your powder one pound at a time or are you buying 4, 6, or 8 pound jugs ? Bullets- are you buying one box of 100 or are you like me and buy two boxes of 1000 at a time ? I buy primers 5000 at a time. You might buy one box of 100 primers.
Then of course just like grocery shopping, do you shop around or do you just go to your nearest gun dealer and pay whatever he asks. I find that components are cheaper at the gunshow. I also sometimes order stuff through off the internet. Powder is almost always cheaper on-line but you have to pay the haz mat fee, but if you order enough powder at once it is still worth it.
You can also get together with several like minded friends and order large quantities of stuff, taking advantage of the discount and then divide it up.
A lot of this stuff depends on the type of shooting you do. I personally shoot the vast majority of my .223 ammo out of an AR15 carbine in defensive type courses of fire. I don't need absolute pinpoint accuracy. I need decent accuracy, but if I can shoot a 5" group at 200 yards, that is fine. Other people shoot NRA Highpower matches where they are shooting from positions out to 600 yards. They obviously have higher standards than I do. I also own a couple precision rifles in .223; A Bushmaster varmiteer and a Tikka Bolt gun. In those, I use different components and different loading methods becasue I am demanding much greater precision and I also am not blowing through hundreds of rounds in a range session. I have a set of brass that I use only in those rifles that never sees my AR15s. Then I do a little varmint hunting with a Remington 788 in .223. Again, different components. I want highly frangible varmint bullets like the Hornady V-Max. But, for coyotes, I don't need the last drop of accuracy, so I use my standard range brass. The cost of each of these loads is highly variable.