I have an IS250 Auto 07 plate with 80,000 miles on the clock for 5 years now. Apart from wear and tear items like pads, discs, callipers and oxygen sensors it has never had a single engine part replaced.
Yes the parts are expensive but these cars are solid..... FSH is a must and there is a is250 buying guide on the form too.
Unless you have a deep dislike of auto's I would advise you to buy an auto. It suits the car better, cheaper to tax and run.