Time Efficiency and Accuracy Issues
I had the experience recently where a client just wanted us to translate small paragraphs on about 120 pages of a website. What is difficult here is that there is no efficient way of accurately counting the words that need to be translated without having access to the source files. Simply downloading the htlm pages and sending through a word counting program yields grossly inflated results. In the end, to guarantee that only the words she wants translated will be considered in the quote, she is spending precious hours of her day copying and pasting the text into a word doc because she doesn't have access to the source files and doesn't know how to get them, and without them, the project gets slowed down significantly for reasons like this. :(
Get in touch with web developer
My personla experience is that whenever the cleint is not too savy about websites they are generally happy to put you in contact with the webdeveloper who certainly can provide you with all source files that involve the site. I have received rather curt responses from clients when i ask for access to their content manager on the site. However, if the cleint wants you to publish the translation i believe that there is no other way.