Like most Magic: The Gathering cards, the value of Saproling 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 (Modern Masters 2017 Tokens)
Untap a land by tapping your Kiora's Follower to untap it and then keep tapping the Follower each iteration
Multiple early Sahagin in particular will just outrace a majority of decks, and its not actually difficult to find expensive noncreature spells since the set is built with this theme in mind
The sacrifice ability occasionally came in handy, guarding against mass removal even though it was never the primary motivating factor, and it was hard for decks running him to justify keeping the necessary mana untapped until very late in the game
Contents: TheAdventures in the Forgotten RealmsSet Booster Pack contains 12 Magic cards, 1 Art Card (includes a D&D monster stat block on the back in 33% of packs), and 1 token, ad card, or special card from Magic's history (a card from "The List")
You can find the metropolis lands in traditional foil and non-foil in Set and Draft Boosters