i just bought one from rockauto.com for under 30 bucks, go to their website, type in your model etc, the rear joint is under "ball joints", its the rear upper, the mevotech brand comes with the mounting bracket, i have one sitting next to me. still no easy install, but id do it 3 times before id pay somebody 540 bucks to do it. if you DO need the whole arm assembly im sure you can get it at the dealer for about half that quote.
2000 White V8 WJ LSR-6in-35's-LA's-242HD-Warn SOLD and missed very badly
06 GTO - BC Coilovers, JBA Catless mids, Svede Intake