I would like to know how much do you charge for Spanish-English translation in the U.S.?

I have been asked to quote per word cost for translating a Spanish novel(100 000 words) by its author. I am trying to figure out what will be better, I think per word charge will be fair for both me %26amp; the client but want to know others opinion. Also I just need a range not a fixed price. So irrespective of the states/locations just give an idea of the maximum %26amp; minimum that can be charged. Or let me know if USD 0.10 per word is reasonable, very expensive, or very cheap???I would like to know how much do you charge for Spanish-English translation in the U.S.?
I've only done translations as part of my job in social work, but there's a website for professional and aspiring translators, www.proz.com, where you should be able to get some good information.