No matter what kind of wall covering is on your wall, the #1 determining factor on how much it will cost to remove it will always depend on if the wall underneath it was prepared properly.
In order for a wall covering to be stripped properly, the wall has to be sealed with either an oil primer or sizing. By doing this, the barrier created will prevent the wallpaper glue from soaking into the wall and permanently adhering itself. If the glue is allowed to soak into the surface then removal is bound to be very difficult.
Wallapaper removal can be best summed up in one word........PATIENCE! If you don't have it, you may have a difficult time ahead of you. I have removed thousands of feet of wallpaper and patience is, by far, the most necessary trait someone can have when tackling this project.