There is no such vehicle as a "2011 RS".
In 2011 the only models on the market were LS, LT and SS optioned as "1" or "2" in each respectively.
Since you mentioned the "orange interior", only two models were sold with that interior;
The 2LT and 2SS. With the stated price of 15k, you are looking at a 2LT model.
The 2011 2LT with $35k miles is worth $15,750 @ retail therefore, their sale price of $14,900 is more than reasonable. I highly recommend installing a catch can on the V6 by a local performance shop endorsed by one of the four
Texas Camaro Clubs and getting the valves cleaned asap.
Edit:
Bob Tomes Ford? Be sure to hit up the DFWCC or LSCC for owner support