I took my boat trailer apart and had all the parts galvanized. It was $ .21 a pound to burn the paint off the parts I couldn't sandblast in my booth and $ .35 a pound to hot dip galvanized.
They actually burned the paint off in the molten zinc tank, kept at 850°. They then acid bathe the metal, returning it to raw steel before starting the galvanizing process.
I had every part of a 21-foot boat trailer done, including the axle and springs, for under $500. It'll patina to a dull gray but can easily be brightened with a wire wheel. It'll never rust again.