More than two players) formats in mind, and, like goad, likely won't appear in Standard any time soon, it does see play elsewhere
Like most Magic: The Gathering cards, the value of Spike Tiller 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 (Time Spiral)
This can often lead to inflated prices, that drop heavily once demand wavers
based players used TCGPlayer mid or market when it comes to trading, however I have seen people mention Card Kingdom, Amazon, and Ebay
Finkelstein was a good fit for Endrek Sahr, though my original intention was to have the skull break out over the right side of the card frame