Cheapest I have seen is $2.99 EACH for ONE OUNCE. That is $47.84 a pound. Copper on the market is like $3.85 a pound. So in reality one ounce of copper is worth about 24 cents an ounce. With mintage costs at about 20 cents each, I can't see spending over $1 each for them.
I dont think you are going to be able to find them for too near spot price. The best prices I've seen are at provident metals http://www.providentmetals.com/bullion/copper/1-avdp-ounce.html They have some for $1.19 each now
The problem with copper bars or rounds is the premiums are too high and realistically these shouldn't be used as any type of investment of sorts or even a store of wealth as the premiums make it not impossible, but very unrealistic you will ever even break even. That being said some of them are very nice looking rounds copying older US coinage, etc and I have a few I bought for this reason mostly for my children as if they rough up a one once copper coin it isn't that bad a loss to me. If you want to perserve wealth or have copper as an investment just sort cents a box is $25 and around where I live roughly $7-$12 of the total cost will be copper cents you can set aside and save. Saving copper cents has no real downside except time invested as they will always still be worth that cent (inflation issues aside). If they ever do debase them or demonitize which this type of legislation to replace them being proposed more and more frequently it's only a matter of time until they really start to disappear. Plus it's just plain old fun sorting them out for my family at least and they add up very fast even just sorting by hand picking up a box or two here and there.
If you want to make money with copper, scavenge wire and pipes. However, what you spend on gas hunting for it will probably negate any profits.
If you really want to buy it for spot, buy a contract. You get to pay for storage and shipping on that too, but you still bought the copper for spot. Then you could invest in all the machinery to make your own rounds and bars and sell it for way less than everyone else.
