The phrase 'shared cinematic universe' is thrown around so often by the studios these days that its easy to forget that until recently, 'the first in a planned trilogy' was usually the default quote when referring to a recently-announced blockbuster. With hundreds of millions of dollars involved in creating a summer blockbuster, the studio executives will always have one eye on the franchise potential of their productions. Not everything has to be turned into a trilogy or a franchise, that just seems to be the way the movie business is heading. Of course, if a trilogy comes to a logical conclusion then there is always a chance that it will be rebooted or given a long-delayed sequel; Indiana Jones, Die Hard and Rambo all got fourth movies after a long absence, the Bourne series continued without Matt Damon and even the 30 year-old Terminator franchise is undergoing its second reboot in less than a decade. In the movie business you have to spend big to win big, and if there's money to be made from an existing property then Hollywood will attempt to squeeze every last drop of profit out of it, which is why we're now expecting a Star Wars and Spider-Man movie every year. A recent report that leaked the financial details surrounding The Hobbit movies (more on that later) served as the inspiration for this article that will count down the ten most expensive trilogies ever made. Let's not forget that there are also two massively expensive trilogies currently in the works that will easily shoot their way towards the top of the list in the years to come; Star Wars Episodes VII, VIII and IX along with James Cameron's upcoming Avatar trilogy but for now these ten trilogies are the costliest. There are several familiar franchises and a couple of very surprising inclusions in this list that demonstrates just how much money movie studios are willing to spend on a set of three movies, knowing that they are virtually guaranteed to make a huge return on their investment. What do you make of the ten most expensive trilogies of all time? Are there any surprising inclusions? Are there any missing franchises you thought would make the list? As always, sign off in the comments below.