Normal costs: Oil change 50-100, tires are about 350 a piece and are rated for 15,000-20,000 miles I believe.
I daily drive my Z (manual) and very happy with it, it can be a pain some days with traffic but when the traffic breaks up I love it.
Maintenance cost are probably around the same as other cars, the Z does not really use anything special.
Define large?
Welcome, Houston Z here also.