Demographics seem to play a role in it too. Assuming yours is a GT, $11,000 trade seems awfully low. I just checked NADA and average trade in is $14,150 in my zip code. This is assuming a mid-level GT. An 09 with all else equal is $16,225. I see these things priced all over the place, some people think they're worth a mint, and some don't place much value on them. Just recently on Autotrader one crazy dealer had a base V6 with like 50k miles listed at $23k.
-2009 G8 GT, Stryker Blue Metallic; Spectre CAI; Solo axleback; X-pipe; Diablo tune; Koni Sport; Whiteline poly strut mounts, Polished Camaro 20's, DOD delete with LS3 cam
-2009 G8 GT, Magnetic Gray Metallic; Stock (SOLD)
-2007 Saturn Aura XR, Black; Stock
-1998 Trans Am, Black; 3:73's; SFC's; Lowered with Bilsteins all around; AR Torque Thrust II (SOLD! 7-28-17)