Cheapest priced copy (Masters 25): $0.49 at Card Kingdom, near mint, their price list as of .
Izzet Chemister 
Creature — Goblin Wizard · 1/3 · Rare · Forgotten Realms Commander · #130
Haste
{R}, {T}: Exile target instant or sorcery card from your graveyard.
{1}{R}, {T}, Sacrifice this creature: Cast any number of cards exiled with this creature without paying their mana costs.
Legal inCommanderLegacyVintage
Not legal inBrawlStandardPioneerModernPauper
4 printings · $0.49 to $1.99 at Card Kingdom
| Set | Number | Rarity | Card Kingdom | Foil |
|---|---|---|---|---|
| Masters 25 | 138 | Rare | $0.49 | $1.99 |
| Forgotten Realms Commander | 130 | Rare | $0.49 | — |
| Commander 2017 | 26 | Rare | $0.49 | — |
| Commander Legends: Battle for Baldur's Gate | 798 | Rare | $0.49 | — |
6 rulings from Wizards of the Coast
- 16 March 2018You must cast any of the exiled cards you wish to cast while Izzet Chemister's last ability is resolving. You can't cast them later in the turn. A sorcery cast this way will be cast at a time you normally wouldn't be able to.
- 16 March 2018If you cast a card "without paying its mana cost," you can't pay any alternative costs. You can, however, pay additional costs. If the card has any mandatory additional costs, such as that of Tormenting Voice, those must be paid to cast the card.
- 16 March 2018Any of the cards you don't cast will remain exiled.
- 16 March 2018If the card has {X} in its mana cost, you must choose 0 as the value of X when casting it without paying its mana cost.
- 16 March 2018The last ability of Izzet Chemister only lets you cast cards exiled by that card. If Izzet Chemister leaves the battlefield before you activate that ability, the exiled cards are lost forever.
- 16 March 2018You cast the exiled cards one at a time in any order. Later spells can target ones you cast earlier. None of the spells resolve until after you're done casting them all.