Printers and Other Nonprofits

Is it worth calling on a nonprofit? I go back and forth on this subject.

Nonprofits spend money but their frugal and often quirky ways tests the patience of their vendors.Years ago, I sold a job to the American Red Cross in Framingham, MA and then got a letter from their president asking me to return all profit made on the job as a gesture of goodwill. This after putting me through the ringer and sending my idea out to bid. A different gesture came to mind and I politely declined.