My husband always reacts negatively to anything I want to do to the house. He thinks of the expense and the inconvenience, and I hear "NO," or at least a huge, dramatic sigh. Sometimes, once it's done, he really does like it.
There are inexpensive ways to take wallpaper off a wall, and some of those ways you've already heard about in other posts. It's a nuisance, but you'll be MUCH happier with the result if you prepare the wall properly before you paint. It's worth the time and energy.
When you start removing the wallpaper, try to get a big, clean piece of it and set it aside. Later, when you have time, use it as a background for a framed photograph of your husband's family. You don't say whether your MIL is still living, but I know of so many people who have altered a family home, and it turns out that Ma and Pa were delighted to see the change!