What is this card worth

// Adventure: a creature and a spell on one card, nothing on the back Monster Manual // Zoological Study SLD 1782 $14.16 Borderless // Adventure: a creature and a spell on one card, nothing on the back Monster Manual // Zoological Study HBG 217 No price yet Alchemy // Adventure: a creature and a spell on one card, nothing on the back Monster Manual // Zoological Study CLB 242 $8.72 // Adventure: a creature and a spell on one card, nothing on the back Monster Manual // Zoological Study PCLB 242s $12.47 Prerelease // Adventure: a creature and a spell on one card, nothing on the back Monster Manual // Zoological Study CLB 591 $9.16 Extended art Booster Fun