You really need to talk to an attorney about your specific situation, but deficiency judgments are rather rare in Washington assuming the security document was a deed of trust.
If there is a deficiency judgment, you will likely be responsible for some costs, primarily attorney fees and other foreclosure costs. But typically your responsibility for costs ends at the point of the foreclosure sale, not the later sale where the bank lists the property using an agent.
Again you need to talk to an attorney. Your being liable for a deficiency will depend on specific facts, including your income/assets and type of loan (e.g. USDA).