Cheapest priced copy (Duel Decks: Phyrexia vs. the Coalition): $0.35 at Card Kingdom, near mint, their price list as of .
Thornscape Battlemage 
Creature — Elf Wizard · 2/2 · Uncommon · Planeshift · #94
Kicker {R} and/or {W} (You may pay an additional {R} and/or {W} as you cast this spell.)
When this creature enters, if it was kicked with its {R} kicker, it deals 2 damage to any target.
When this creature enters, if it was kicked with its {W} kicker, destroy target artifact.
Legal inCommanderModernLegacyVintage
Not legal inBrawlStandardPioneerPauper
7 printings · $0.35 to $15.99 at Card Kingdom
| Set | Number | Rarity | Card Kingdom | Foil |
|---|---|---|---|---|
| Duel Decks: Phyrexia vs. the Coalition | 42 | Uncommon | $0.35 | — |
| Modern Masters 2017 | 142 | Uncommon | $0.35 | $0.49 |
| Planeshift | 94 | Uncommon | $0.69 | $15.99 |
| The List | MM3-142 | Uncommon | $0.35 | — |
| Time Spiral Timeshifted | 87 | Special | $0.49 | $3.49 |
| World Championship Decks 2001 | jt94 | Uncommon | $0.69 | — |
| World Championship Decks 2002 | bk94sb | Uncommon | $2.49 | — |
10 rulings from Wizards of the Coast
- 14 March 2017You choose whether to kick a spell as you cast it, and you pay that much along with the spell's mana cost at the same time. Kicking a spell is always optional.
- 14 March 2017Kicker costs don't change a spell's mana cost or mana value.
- 14 March 2017You can pay any particular kicker cost only once. You can't pay it multiple times to get multiples of either triggered ability.
- 14 March 2017If Thornscape Battlemage is put onto the battlefield as the result of a spell or ability, there's no opportunity to kick it.
- 8 November 2024If a spell's kicker cost was paid, the spell is "kicked."
- 8 November 2024If a card or token enters as a copy of a permanent, the new permanent isn't kicked, even if the original was.
- 8 November 2024To determine a spell's total cost, start with the mana cost (or an alternative cost if another card's effect allows you to pay one instead), add any cost increases (such as kicker), then apply any cost reductions. The spell's mana value remains unchanged, no matter what the total cost to cast it was.
- 8 November 2024If you copy a kicked spell on the stack, the copy is also kicked. If the copied spell is a permanent spell, the token the copy of that spell becomes when it enters is also kicked.
- 8 November 2024If you put a permanent with a kicker ability onto the battlefield without casting it, you can't kick it.
- 8 November 2024The kicker ability doesn't let you pay a kicker cost more than once.