[Maroon 5.0 LX]

There is nothing wrong with getting a 4 cylinder Mustang. If that's the body style you want, go for it. Seems most folks Have to have the V8, which is nice, but you have to consider the cost factors as you have.

Later on, as insurance rates are within your budget, you can always move up. Just make sure the car is in decent shape so you don't have to put a load of money in it to keep it on the road.