Costs or extras with lift kits?

Hello all

Not as many people actively on here as I expected. Anyways, when installing a lift kit, what all else is needed? I just read an article on here about a lift kit and all the parts necessary for the install. I am not sure what all of them were. How much would it cost average to get say an 8in lift on a 4wd 2007 F-250? 12in? As I have atleast 4 months to go until I get home and get to actively go to shops I just wanted to get some numbers down before heading out. What else should be installed with a lift kit?  

Thanks,
Chris