Lots of fun bouquets, cakes, balloons and flowers etc for parties. However: Store policy stated that customers cannot ask to inflate their own balloons (not purchased at this location) So Where else can one go?

You also rent the kit from ABC Rental

Stop and Shop does it, depending on the balloon material they have different prices, but it's not outrageous prices

You can purchase a balloon kit that includes a compressed tank of helium to inflate your own balloons. Michaels, Target, Walmart, BJ's or Costco sells them. Other places would be some party store like iParty or Party City. Amazon sells them as well.