Can someone please help me!!?

I want to buy a used 2005 Scion tC at a dealership. They are offering it for $11995, and i want to know what is the lowest i can talk them down to? i can afford 11995 but it would be really tight on my budget. its the one i really want and edumunds true market value is $9500. what should i do? ive never financed a car before so im really nervous and need advice!!