Yeah, thats about 60% of what they sell for new. I think its a decent deal. Even better if you could get them for $400.
Just be advised that the drop that guys has on his car looks atrocious with OEM wheels. You will need some nice aftermarket wheels so your car doesnt look 'tarded. An adjustable panhard bar should be on your list too.
2011 Mustang GT M6 3.31s
Matt HONEYCUTT Tune, Lethal Off-Road X, GT500 axlebacks, J&M LCAs, UPR UCA, Whiteline LCA relocation brackets, Eibach Pro-Kit Springs, Koni STR.T shocks/struts, GT500 strut mounts, SR Strut Tower Brace
Best 1/4 E/T (05/18/14 MIR - no tune, X-pipe, or UCA): 12.920 @ 109.40 mph (2.059 60ft)