Jordan,
I paint some blades and cranks. I can tell you this, you will need to paint tons of them to actually save money. I do it for the fun of catching fish on a colorado blade that I painted, or a crank that I painted because I couldn’t find the color in stores.
For fine detail, you will need a good airbrush and compressor (the little propelant cans work but they’re spendy). For most uses, you can get by with standard acrylic airbrush paint, but for blades I’d consider air brush powder (which requires you to heat your blades).
It will take some time and getting used to, to get good at it. I’m far from good at it yet. I do cranks more than blades. I haven’t really had a problem finding blades that fit my needs. Cranks on the other hand, I could use about 500 more