The overall cost and fees of the E2 visa depends on whether you are currently residing in the U.S. or outside. For those who have secured jobs in the U.S. under a different visa status, you can just file an I-129 and have your status modified the moment your petition is approved.
However, if you are currently residing and working outside the U.S., you must first go through consular processing. This needs the appointment with the U.S. consulate or embassy in your home country and the scheduling of an interview with a consular officer. This will also require you to fill up an online nonimmigrant visa application.