Cheapest priced copy (Double Masters): $10.99 at Card Kingdom, near mint, their price list as of .
Spellskite 
Artifact Creature — Phyrexian Horror · 0/4 · Rare · Commander Legends: Battle for Baldur's Gate · #873
{U/P}: Change a target of target spell or ability to this creature. ({U/P} can be paid with either {U} or 2 life.)
Legal inCommanderModernLegacyVintage
Not legal inBrawlStandardPioneerPauper
9 printings · $10.99 to $64.99 at Card Kingdom
| Set | Number | Rarity | Card Kingdom | Foil |
|---|---|---|---|---|
| Double Masters | 289 | Rare | $10.99 | $11.99 |
| Commander Legends: Battle for Baldur's Gate | 873 | Rare | $10.99 | — |
| Judge Gift Cards 2017 | 7 | Rare | — | $64.99 |
| Modern Masters 2015 | 230 | Rare | $10.99 | $13.99 |
| New Phyrexia | 159 | Rare | $11.99 | $34.99 |
| Secret Lair Drop | 277 | Rare | $14.99 | $12.99 |
| Secret Lair Drop | 587 | Rare | — | $12.99 |
| Secret Lair Drop | 2325 | Rare | $16.99 | $17.99 |
| Secret Lair Drop | 2340 | Rare | — | $29.99 |
6 rulings from Wizards of the Coast
- 7 August 2020If a spell or ability has a variable number of targets, you can't change the number of targets.
- 7 August 2020If Spellskite leaves the battlefield before its ability resolves or otherwise becomes an illegal target for the target spell or ability before its ability resolves, no targets are changed.
- 7 August 2020You can activate Spellskite's ability even if Spellskite isn't a legal target for the target spell or ability—or even if that spell or ability has no targets. In this case, no targets are changed.
- 7 August 2020If the spell or ability has multiple instances of the word “target,” you choose which one target you're changing to Spellskite as Spellskite's ability resolves.
- 7 August 2020If a spell or ability has multiple targets but doesn't use the word “target” multiple times, such as the ability of Deepglow Skate, you can only change one of the targets to Spellskite.
- 7 August 2020If changing one target of a spell or ability to Spellskite would make other targets of that spell or ability illegal, that target can't be changed to Spellskite.