If you want to know about olefin price, you can refer to this site: http://www.lookchem.com/news/price/2010-6-22/394.html.
Propylene (CAS.NO.115-07-1)(refined level) : 40.12 – 40.38 cents (usd)/pound
Ethylene (CAS.NO.74-85-1) : 31.255 – 31.495 cents (usd)/pound
Methane–Carbon Dioxide: Conversions to Syngas and Hydrocarbons, by:
Nor Aishah Saidina Amin, Istadi, Tung Chun Yaw, Ruzina Isha