Which exact version of the Secteur is this bike?
Given that Specialized tends to have distinct color schemes for different models and years, I'd say it's a 2013 Compact, which I think is the base model (higher models get 'sport', 'comp', 'elite' etc. appellations).

Bicycle Blue Book 2013 Specialized Secteur Compact.

Drive-train looks original except for the large chainring. 

Bicycle Blue Book gives you a rough guide to value, but ultimately a bike is worth what someone will pay for it.



Update: There appears to be some damage to the drive side seat stay. At first I though the paint was just flaking but on closer inspection it seems the stay may be bent. 

If the seat stay is in fact bent, buckled or dented do not ride the bike!! You would risk the back end collapsing or the rear wheel becoming misaligned and jamming.

If that seat stay is damaged I'm afraid the frame is trash. If someone one Craigslist sold it to you in that state you would have at least a 'moral' and perhaps legal standing to demand your money back, and may have been illegal depending on location.