i basically did a stage 2 with harley cnc heads. not 100% sure of total cost as the stage 1 portion of it was figured into my deal when i bought the bike. cold as hell here so only 92 miles on the bike but it was worth every penny to me. i would have not bothered with the cam without the heads. this being said my bike is a rushmore. pre rushmore id say the stage 2 would be worth it without heads
Far as cost, depends alot on what you go with, (pipes ac, cam, and who does the work) I got mine with stage one in the deal, later on, added cam, made a significant difference to me , with no head work. Have a 14 limited, went with the 54 g Andrews