Actually, it's a give or take in terms of a school like NYU over LFS for an MFA.
NUY is a very, expensive school, as is Columbia. LFS is actually cheaper in terms of tuition and you get out a year earlier.
I recently visited LFS in London, and the city itself is doable financially, even though the pound overwhelms the dollar. Housing is actually cheaper in parts of London such as Hackney or Clapton Pound then in an area surrounding Washington Square Park or parts of the lower east side. Housing in parts of London are on par with prices in Brooklyn. Again, a give or take.
NYU is a school I was considering for motion picture preservation, but really, the school is as expensive as law school and is TERRIBLE with financial aid (according to a professor I spoke to, NYU has NEVER written a single grant for the cinema studies department!)
In actuality, America is probably the most expensive place in the world to go to grad school in terms of tuition for film school.
Living expenses are a different story, but again, it's how you handle yourself. I also know that at LFS and other schools such as the University of London's school Goldsmount, your allowed to get a work permit for approx 20-30 hours a week...so if you get yourself a paying internship or other job through the school while attending (which is common according to a friend that attends LFS), you don't have to worry about not being a resident to get pay. You can also easily find work at grocery stores, or other places.
LFS is also one of the last school in the world to shoot on 35mm. You also complete more films in your tenure there than in the three years spend at NYU, and again, the tuition is much cheaper.