There is one Trick in the game on on how to get the required Element in the store every time. So,when you enter the "Shop Portal", do not go straight to the seller, go to the chest with Artifacts and select the Artifact you need again, then go to the seller and buy the required Element. Then leave the seller and go back to the chest with Artifacts, select the Artifact you need again and return to the merchant. Then, using the "Dice", update the items in the Store and you will again be provided with the required Artifact. And you can do this several times. Below is a video example with the "Utroms" Elements

Full Game

P.S.:

Sometimes in some shops the chest with Artifacts can be opened only once,I don't know why this happens.