Why are translation prices so different?

There are so many good points in this sound and balanced analysis! I especially liked the 2nd half.

http://www.localversion.com/en/localization/60-translationprices.html

Localization is not particularly expensive, but your favorite translation partner will probably not be the cheapest one.

Professional translators earn 30% below average salaries in Western countries. When clients put excessive pressure on rates, they are actually choosing to work with localizers who earn even less than that, which leads to high risks of wrong translations, poor style, miscommunication, or even legal issues. ...  Chances are high that those translations end up being assigned to cheap, junior translators who will rush to translate as many words as possible, with little care and very poor results.

Accurate, specialized translations demand much more time and expertise. If your English texts are clear, natural and carefully written, your foreign users expect exactly the same in their own language.

How and when to raise your rates

by Corinne McKay
http://thoughtsontranslation.com/2014/02/10/raising-your-translation-rates-how-and-when/

Short answer: with new clients, and when you’re already really busy.
...
If 100% of potential clients accept your rates without negotiating, you could be charging more. 

And here's a neat PROZ page that shows members' average reported rates for all language pairs.
http://search.proz.com/?sp=pfe/rates