6
Most scripts I found in research did not do the translating themselves, but serve as intermediaries to google or bing translation services. These services now charge you by traffic levels, and the websites who sell the script for the most part do not tell you this (because they would not sell as many script licenses then).
I personally will never use such third party services such as Google or Bing and others
for this reason
. Because they translate the content between known sources and destinations, a complete and perfect record of everything can be built from the logs of these servers.
For a script to operate standalone, it would require huge translation databases that would drive the cost of the script into the hundreds if not thousands of dollars.