Try Michaels or Hobby Lobby or any craft supply store. At Michaels, search in the paint supply aisles and at Hobby Lobby, search the aisle that sells paint and the beading necklace & etc aisles. I just purchased some small containers with the black lids from Hobby Lobby to put my NYX pigments into. It was sold six in a bag for under $2.00 ($2.99 with a 40% off coupon).
HTH