is this 2000 GT a good deal?

No, for that price I've seen FL cars go for the same and be a 03/04 GT with it being sonic blue/silver/white or black.

Hell if you had like $2000 more I am thinking about putting my '99 up and its pretty much set up for DDing and AutoX's.
 
I think its a good deal. I bought my 02 with 50K miles for $700 more. That car has less miles and looks like it has been maintained pretty well.
 
Its about $1,000-$1,500 too high IMO. Sure the mileage isn't bad, but the car is already 11-years-old and there's nothing really special about it. Buy it if you wish, but there are better deals to be had.