I plan on doing the same thing. I have the black costco card which means that i would get back 1% of the sales. Which should be coming soon. I will spend that then turn around and ask for my membership fees back.
I was at the store where Erik was shot at only about a 1/2 hour before the shooting went down. I would go to costco about once every 2 weeks. I haven't been back sense the shooting.