Like most Magic: The Gathering cards, the value of Sword of Light and Shadow 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 (Kaladesh Inventions)
A few more opinion writing starters
Thematically, this is supposed to represent the creature surviving combat, but the mechanic does not care how the creature was tapped
Whether Reviving Dose should see play would depend on the specific strategy and synergy within the deck, but it could be a viable option in the right circumstances
Issues such as food wastage, disregard for group size limits, and attempts to cheat the system and obtain the cards via underhanded means, to name but a few, were rife at McDonalds outlets throughout the country