Cheapest priced copy (Commander Legends: Battle for Baldur's Gate): $0.49 at Card Kingdom, near mint, their price list as of .
Arasta of the Endless Web 
Legendary Enchantment Creature — Spider · 3/5 · Rare · Theros Beyond Death · #325
Reach
Whenever an opponent casts an instant or sorcery spell, create a 1/2 green Spider creature token with reach.
Legal inCommanderPioneerModernLegacyVintage
Not legal inBrawlStandardPauper
13 printings · $0.49 to $12.99 at Card Kingdom
| Set | Number | Rarity | Card Kingdom | Foil |
|---|---|---|---|---|
| Bloomburrow Commander | 205 | Rare | $0.59 | — |
| Commander Legends: Battle for Baldur's Gate | 817 | Rare | $0.49 | — |
| Commander Masters | 885 | Rare | $0.49 | — |
| Foundations Commander | 188 | Rare | $0.59 | — |
| Marvel Universe (Master Weaver, Web Protector) | 32 | Mythic | $3.49 | $4.99 |
| New Capenna Commander | 279 | Rare | $0.49 | — |
| The List | BLC-205 | Rare | $0.49 | — |
| Theros Beyond Death Promos | 165p | Rare | $1.79 | $4.49 |
| Theros Beyond Death Promos | 165s | Rare | — | $2.49 |
| Tarkir: Dragonstorm Commander | 244 | Rare | $0.59 | — |
| Theros Beyond Death | 165 | Rare | $0.49 | $2.49 |
| Theros Beyond Death | 325 | Rare | $3.99 | $12.99Out of stock |
| Theros Beyond Death | 352 | Rare | — | $0.99 |
One ruling from Wizards of the Coast
- 24 January 2020An ability that triggers when a player casts a spell resolves before the spell that caused it to trigger. It resolves even if that spell is countered.