Cost is certainly a factor; a calculator makes it easy.
There are quite a few out there, here is two.
Use whichever you like or runs the quickest for you.
http://www.handloads.com/calc/loadingCosts.asp
http://ultimatereloader.com/tools/reloading-costs-calculator/
Finding what reloading components works for you may take a while, and it may cost a bit more than a production run.
Finding an inexpensive bullet that meets your needs is one of the easiest ways to reduce the cost. Also, any cost reduction by buying on sale or in quantity is the way to go.
But you'll want to feel comfortable with your bulk buys, before you stock your inventory.