I'd save that money and find a way to do it yourself. If my son comes to me in 12 years wanting to lift or lower his truck, I'd prefer him to do it himself with my help or even without, mainly so he could learn and respect what he's done. Now if he don't have the sense to turn a screw that of course would be a different story. I don't plan on him being like that, so we'll see how that works out. The only thing I'd say do professionally is get the thing aligned afterward.
I have no problem doing it myself. As we lowered one on our own. None of it seems to be rocket science to me. But the ol' man would rather someone else beat their knuckles up then save some cash at times. Our salty winters dont help anything on our trucks either.