If you have 501c3 status, you may be able to get many online and website-related services at free or discounted prices.
Some also require that your organization is a silver or gold Guidestar member.
Check out Grassroots.org
Bluehost (affiliate link): sign up as a nonprofit
MailChimp is free up to 2000 members
Look at Paypal for Nonprofits
Here are some nonprofits I have developed websites for:
Ageless Alliance: United Against Elder Abuse