A lot of what drives the cost of reloading ammo for you -the individual reloader- is location. While some online sources have excellent prices on components, you have to factor in shipping and hazmat handling (for primers and gunpowder), and even availability, since some online retailers do not mention if an item is in stock or not at the time of ordering.
98% of what I shoot are reloads. The only problem withl ordering powder and primers is the Hazmat fee, doesn't matter if you buy 100 primers or 50 lbs total of primers and powder, it's $25 plus regular shipping fee. You need to make it worth while and order a lot or get a few friends to go in with you, check your local stores for powder and primers first.