It's much cheaper to buy production cranks than build your own. I just dumped approx 200.00 in weights, rings, hooks, and epoxy. I still have to order another 100.00 worth of wood. Tools, paint, and number of other things I can't think of off the top of my head all cost.
I bet my first quality crankbait cost me around 600.00.
I have not fished with a store bought crank in 6yrs, since I caught the first fish on one of mine. It's an addiction that has no cure and if you ever catch a fish on a bait you've made then all hope is lost.