I just bought two, a German and South American (Spanish) version for £40 from a guy in the US.
I will post photos when they arrive. The SA is around 24" x 36" so not a bad size.
I can't afford big money for posters so i may as well put this out there....
There's a quad for sale on ebay uk. Search for : FERRIS BUELLER'S DAY OFF ORIGINAL UK QUAD POSTER 30" x 40" UNFOLDED
It's a bit wrinkled but still cool.
I offered the guy £30 for it.
It's always worth a shot.