What is this card worth

// Adventure: a creature and a spell on one card, nothing on the back Illithid Harvester // Plant Tadpoles HBG 122 No price yet Alchemy // Adventure: a creature and a spell on one card, nothing on the back Illithid Harvester // Plant Tadpoles CLB 564 $0.40 Extended art Booster Fun // Adventure: a creature and a spell on one card, nothing on the back Illithid Harvester // Plant Tadpoles PCLB 76s $1.70 Prerelease // Adventure: a creature and a spell on one card, nothing on the back Illithid Harvester // Plant Tadpoles CLB 76 $0.38