whats this car worth?

[1-QIK-SNK]

I have a guy that said he will sell me his 1990 5.0 mustang. I think it is the
7 up one. It is green with white leather and white conv. top and is a auto. It need some TLC like a good detail job new tires and a tune up. It has between 150-155 k miles. The pass. side mirror(sp?) need fixed(just hanging) and the deck lid has alittle rust. It is basically all stock except for flow junks and UD pulleys. The driver seat is good(no rips or any wear) The pass side has a small rip about 1" long. It did smell like mildew(sp?) inside.
He said it has been sitting along time, but he put a battery in and it started right up, but would not idle. Thats where I think the tune up would come in to play.

Just wondering what you all think of this. I wont get back to the job till monday to get some pics. He told me 1500.00

What you all think?