I should reiterate that "repacks" are put together by the individual stores that sell them. Their availability varies, with some stores almost never having them. Yesterday's repack came from Hobby Off, a store for collectors which mainly has lots of toys and figurines. All of the "Off" stores are secondhand stores, buying from the general public. But before you get your hopes up, know that they pay very little when buying. This does keep prices lower, generally.
They had two baseball "packs" on the shelves, though. Yesterday's was only 100 yen, though today's pack set me back 200 yen. Was it worth it?