The weight of 3 mana is covered by green's mana generation, so it didn't bother me as much as I expected
While non-foil copies are going for $750 or more on TCGplayer, the rainbow foil variant is so rare that there are currently on three listings on TCGplayer, with the lowest being for $1200
Bushmaster, Coiled Henchman Chishiro, the Shattered Blade Ikra Shidiqi, the Usurper Imoti, Celebrant of Bounty Kadena, Slinking Sorcerer Kaseto, Orochi Archmage Lonis, Cryptozoologist Lonis, Genetics Expert Omarthis, Ghostfire Initiate Sachi, Daughter of Seshiro Sakiko, Mother of Summer Sasaya, Orochi Ascendant Seshiro the Anointed Shigeki, Jukai Visionary Shisato, Whispering Hunter Shizuko, Caller of Autumn Sidisi, Brood Tyrant Sidisi, Regent of the Mire Sidisi, Undead Vizier Sivriss, Nightmare Speaker Sosuke, Son of Seshiro The Serpent Society Xyris, the Writhing Storm
You could be playing Sword of the Animist or Shadowspear instead
Then, on another turn, you can cast that spell without paying its mana value (only at sorcery speed)
Ygra, Eater of All looks like it's going to be a fun deck, but it now shares a footprint with another deck in my collection: Mahadi, Emporium Master