Like most Magic: The Gathering cards, the value of Price of Loyalty depends on a few consistent factors: its rarity, the printing and finish (regular or foil), its physical condition, and the set it was printed in (Adventures in the Forgotten Realms)
Tyvar the Bellicose Tyvar turns your mana dorks into legitimate threats
A cards condition is one of the biggest factors in its value, so your price checker absolutely must account for it
not only does it cost less mana than LabMan, but it doesnt require an additional effect to draw a card, and killing it in response rarely interrupts the win since the trigger goes straight to the stack
SOL RING AND ARCANE SIGNET ARE JUST THAT GOOD Sol Ring is the mascot of Commander, and in many ways basically all other ways it probably deserves to be at least a gamechanger, if not banned