op deck yugioh THE NEW BEST IN THE GAME! BRANDED DESPIA UNDEFEATED KING OF GAMES! (Yu-Gi-Oh! Duel Links) The 6 Most Expensive Decks

Regarding the ways to know the price of your cards, you should look at the internet, namely, eBay, or PSA Card Facts or ask people who know something about it

You can obtain the Tapu Fini (1-Star rarity) card by opening Celestial Guardians: Lunala from Celestial Guardians set

Of course, you ideally wont give it back, but its nice that you get a little bonus

Bot/Abuse Policy: Orders placed using bots, automation, or multiple accounts to bypass limits will be cancelled and charged the 10% fee

With a good sea creature commander in Runo Stromkirk and typal support from cards like Serpent of Yawning Depths, the Leviathan has better synergy within its typal home than River Bear