To be fair, those are 100% beef hotdogs that they sell at a loss. There's a reason someone suggested increasing the price despite being met with threats of violence from the CEO (president?) in response for that suggestion.
To my knowledge, I don't think you have to have a membership to get food at Costco. I'm pretty sure the optical shop and pharmacy are available to non-members as well.
You're probably still right about pharmacy but the Costcos around me now require you to scan your membership card at the food court registers before you can order anything.