You can obtain the Snubbull (1-Diamond rarity) card by opening Fantastical Parade from Fantastical Parade set
Unlike Blue Eyes' Kiabaman, Chick is also a one-star monster
And if toughness is your goal, you need some of the highest-toughness cards out there like Unhallowed Phalanx, Charix, the Raging Isle, and Kharis & the Beholder (that last one not being legal for tournament play)
You can only use this effect of "Longirsu, the Orcust Orchestrator" once per turn
Even if these cards were borderline unplayable, this should guarantee that finding one results in a healthy profit
And Cabal Coffers is at least a very strong card, potentially adding a ton of mana, especially in conjunction with Urborg, Tomb of Yawgmoth to make all of your lands into Swamps