I bet they cost more than that at a lot of dealers. I got my silver IS300 at Cerritos Lexus, and the invoice was like 33,700. I was in Nashville recently at Lexus of Nashville South and the ivory white one they had there was 34,700; a thousand dollars over invoice with the same exact options too.
Ira Lexus in Peabody MA had a stripped Graphite IS300 (cloth interior) with a 'winter package' consisting of 16" rims with 4 snows. Package Price: $3500. Those must be some great snow tires!
I don't think Lexus can sell many IS300s at over MSRP, can't be that many fools out there.