There seems to be a listing for Green flat sandals for 0sp. If you go to the shop you can see it's for display only. It can't be bought in the shop or on the listing page. Not sure why it's listed.

Link to the shop here: https://subeta.net/user_shops.php/shop/56385

Shop Search (on the original site) is showing all the items from that particular shop (all items are listed as "display only" and they're all appearing in the search at 0sP)

....it does not show up in the search on Kumos