it's expensive because it's rare. even separate HID bulbs of 6000k/8000k are pretty expensive as well but cheaper than this. this would be good for your foglamps so no problems driving in low visibility condition..
A normal pair Philips 85122 (4300k) will cost you around RM 700 - RM 800, and 85122 Ultinon(6000k) cost RM 1000 - RM 1200 (market prices those have resit and brand new) .....
So you should consider this pair is cheap especialy u can't find it any where else .....