You have wallpaper, and you've decided to paint the walls. What do you do? A question we're often asked is if we cannot simply paint over the paper. The answer is "no".
Well, you can, but remember paint is wet, and wallpaper is, well.. paper. What happens when paper gets wet? Exactly.
If you've decided the paper needs to come off and the walls need painting, you can leave it up to the painters to remove the paper, sure, and they would. But, it is extremely tedious work and time consuming, therefore pricey.