My roommate is helping someone find a good first car with a budget of 7.5k. I suggested this.
It will get you into a good hobby, helps you develop mechanical skills, good portion of the budget is left over, and it is a car that someone could be really proud of with a little beautification even though it is not the best looking year for the Mustang. This could be a good learning experience and provide some family/friend bonding, which is exactly what a first car is supposed to do.
Edit: All these beige suggestions are making me sad.