A City endorsement on your State of Washington business license costs $71 ($74 in 2024). You will pay this fee at the time of application (fee MUST be included for your application to be processed) and the same fee annually to maintain your City endorsement.
Nonprofit Organizations are exempt from the City endorsement fee although they are still required to obtain a State business license and a City endorsement. See this webpage, about half way down, for fee-exempt endorsement.
WA-DOR Business Licensing Service (BLS) may add additional processing fees to cover their processing, postage, and other costs.