Perhaps, this is a question with a simple answer such as "it's what it is" but I was just curious if there were any sensible explanations to the difference in money prizes for open events vs. women's in Beijing. 

As in does it really cost more to invite top male players vs female counterparts because they are accustomed to earning more? Or alternatively, had the prizes been the same, would it have  jeopardized the event's success by risking top male players turning down their invitations?

Source:

http://www.imsaworld.com/site/news_full/6.html