Cheapest priced copy (Dominaria United): $1.99 at Card Kingdom, near mint, their price list as of .
Defiler of Dreams 
Creature — Phyrexian Sphinx · 4/3 · Rare · Dominaria United Promos · #46p
Flying
As an additional cost to cast blue permanent spells, you may pay 2 life. Those spells cost {U} less to cast if you paid life this way. This effect reduces only the amount of blue mana you pay.
Whenever you cast a blue permanent spell, draw a card.
Legal inCommanderPioneerModernLegacyVintage
Not legal inBrawlStandardPauper
4 printings · $1.99 to $3.49 at Card Kingdom
| Set | Number | Rarity | Card Kingdom | Foil |
|---|---|---|---|---|
| Dominaria United | 46 | Rare | $1.99 | $1.99 |
| Dominaria United | 393 | Rare | $2.79 | $2.49 |
| Dominaria United Promos | 46p | Rare | $3.49Out of stock | $2.99Out of stock |
| Dominaria United Promos | 46s | Rare | — | $2.49Out of stock |
2 rulings from Wizards of the Coast
- 9 September 2022Some players may make the mental shortcut that the Defilers effectively turn one of the colored mana symbols in the spell’s cost into a Phyrexian colored mana symbol. Despite the similarity in function, this ability does not cause the spells to have Phyrexian mana symbols in their costs. Sorry, Rage Extractor!
- 9 September 2022You may only pay the additional cost once per permanent spell.