I don't necessarily have to buy my pepperoni at a certain store and I think there are lots of good pepperonis out there. I like Hormel or Boars Head off the top of my head. It is not something that I am overly brand loyal about. Because of Trader Joe's business model, in most cases they will only carry 1 or 2 brands of a product or only their private label. Most groceries or deli markets will have a much bigger selection.
And Volpi is carried many places.