The border, image, Level/Rank, and Attribute of these cards has a rainbow-colored pattern along with a Secret Rare-style name
Best Budget Option Maybe the XenoSkin of the Ultimate Guard boxes is too fancy for your taste, and the Quivers shoulder strap isnt what youre looking for, either

Without further ado, here are the most expensive cards from Bloomburrow so far: #1 Three Tree City $20 #2 Ygra, Eater of All $16 #3 Beza, the Bounding Spring $13 #4 Innkeepers Talent $13 #5 Caretakers Talent $13 #6 Lumra, Bellow of the Woods $12 #7 Maha, Its Feathers Night $11 #8 Rottenmouth Viper $8 #9 Ral, Crackling Wit $6 #10 Dawns Truce $6 #11 Fountainport $5 #12 Emberheart Challenger $5 #13 Stormsplitter $5 #14 Season of Gathering $5 #15 Season of the Burrow $4 #16 Fabled Passage -$4 #17 Patchwork Banner $4 #18 Artists Talent $4 #19 Season of Weaving $4 #20 Into the Flood Maw $4 #21 Mockingbird $4 #22 Dragonhawk, Fates Tempest $3 #23 Kitsa, Otterball Elite $3 #24 Warren Warleader $3 #25 Scavengers Talent $3 #26 The Infamous Cruelclaw $3 #27 Iridescent Vinelasher $3 #28 Eluge, the Shoreless Sea $3 #29 Season of Loss $3 #30 Heartfire Hero $3 Those are all the big money cards from Bloomburrow as of the time of writing
And should it die, you're down a handful of lands for nothing
while allowing the deck to function without him, the deck fires on all cylinders when he is active