These four games are the only standard Playstation 1 titles that were released in cardboard cases.
“Tekken”, “Total NBA `97” and “Warhawk” were also released in normal jewel cases, but I have never seen “Mortal Kombat 3” in any other variant.
“Total NBA `97” is a bit different from the others. It has blue as basic colour and a piece of basketball rubber glued to the front cover.
None of these games are particularly rare or will cost you much money.