Washington law does not favor spousal support, but judges and lawyers all know that sometimes a spouse will be awarded maintenance or spousal support on top of child support, or even in a case where the spouses don't have any children. Here are some guidelines as to how that might work:
First, the "rule of thumb" is that a judge MIGHT (not will, but could) consider one year of support for every three years the couple were married. A 9-year marriage, if the judge relies on the general idea, would result in three years of spousal support. This sounds pretty simple, but the judge isn't automatically going to say "Hey pay your spouse every month for the next three years...." The judge will look at other factors, including relative income, the position the two of you were in before you were married, and so on.
Second, in applying those factors, the judge CAN (but does not have to) give your ex-spouse some of your separate property. In Washington, if you buy a house or build a retirement fund during your marriage, that property and money are community property. A house or IRA that you owned before you were married is separate property. If a judge feels it would be fair, the judge could give your ex spouse half of that IRA even though it's not community property.
Third, the judge will focus on where both of you would be if you had never been married. If you worked for 15 years, while your ex stayed home with the children, the judge will try to calculate what kind of earnings that your ex might make now that she's going back to work. If your ex left a high-paying job to stay home, then she would be entitled to more than if she still hasn't earned a college degree. The judge might ask you to support her until she can reasonably support herself in the way that she would have without the time she spent working for the family.
Fourth, if your ex cannot take care of themselves due to illness or lack of opportunity because of educational or other limits, then the judge will want to make some award of spousal support to be sure your ex will be okay in the future. The judge has the discretion to go into your retirement or ask you to pay for their support for whatever your spouse might need, such as a college degree, to become independent. Often a judge will ask for an award of support until social security or disability is available to your ex, or until classes can be completed. A judge might also award a lump sum of property totaling some year's living expenses so that your ex has some time to get back on their feet.
Finally, arguing about spousal support tends to be expensive not only because of the amount awarded, but because the support is in the judge's individual discretion. In law, time is literally money. Lawyers have to spend more time arguing and researching issues that are in the judge's individual discretion. The uncertainty created by the lack of clear, bright-line legal rules can easily add up to a lot more fees for you. Your spouse's lawyer might argue that you should pay additional spousal support to keep your ex as comfortable as she was when you were married, and keep paying until your children graduate high school. Your lawyer might argue instead that you should only pay support to replace the salary she was making as a waitress when you were married, and only for a short time. The hearings and briefs and research and arguments all take time, and the judge is going to come down somewhere in the middle (or, since it's up to the judge's individual discretion, make up a new plan that no one asked for). Spousal support is an area, unlike child support, where even very good lawyers really don't know how your case is going to end. That uncertainty makes it a risk, and increases the costs to litigate.
You can avoid this by setting up a reasonable child support with your ex. Most parents feel comfortable supporting their children. And the law on child support is much more clear. Avoiding the fight about spousal support can help you both move on faster, and you can keep more of the money that you didn't have to spend on legal fees.