A lot of resources went into development of Maemo 6 and N9's design to suit the OS. Other parts inside drive the cost even more. SoC, 2 year old or not, is doing the job flawlessly inside the N9 and that's what you pay for, the perfect UX.

Also, do keep in mind that since Elop arrived at Nokia, his whole purpose was to drag away sales from the N9 and get as much money back as possible spent in R&D. There were 2 ready devices and only one released and Nokia was in drought for a year. Even with the high price, the phone experience positive reception, and is selling like a fat kid eating at McDonald's. Nobody gives a crap if it runs a 2 year old chipset if all is flawless and unique.