Usually price is in line with power ergo the pricier duals should cost more
Magic: The Gathering have fixed poison by adding two new mechanics toxic, and corrupted

Tymna the WeaverTymna the Weaver Ragavan, Nimble PilfererRagavan, Nimble Pilferer Purphoros, God of the ForgePurphoros, God of the Forge Kinnan, Bonder ProdigyKinnan, Bonder Prodigy Winota, Joiner of ForcesWinota, Joiner of Forces Azusa, Lost but SeekingAzusa, Lost but Seeking Jodah, the UnifierJodah, the Unifier Muldrotha, the GravetideMuldrotha, the Gravetide Gix, Yawgmoth PraetorGix, Yawgmoth Praetor Kraum, Ludevic's OpusKraum, Ludevic's Opus Ishai, Ojutai DragonspeakerIshai, Ojutai Dragonspeaker Bruse Tarl, Boorish HerderBruse Tarl, Boorish Herder Adeline, Resplendent CatharAdeline, Resplendent Cathar Inalla, Archmage RitualistInalla, Archmage Ritualist Godo, Bandit WarlordGodo, Bandit Warlord Sram, Senior EdificerSram, Senior Edificer Varragoth, Bloodsky SireVarragoth, Bloodsky Sire Mangara, the DiplomatMangara, the Diplomat Loran of the Third PathLoran of the Third Path Venser, Shaper SavantVenser, Shaper Savant Of course, all this means nothing if you're really, really excited to get your hands on the Final Fantasy'd version of your favorite commander

The spirits of these three 'Egyptian God' monsters are so powerful that Pegasus had to use the protection of the Millennium Eye to create the three cards without any harm from the spirits