Cheapest priced copy (March of the Machine Commander): $0.49 at Card Kingdom, near mint, their price list as of .
Battle Screech 
Sorcery · Uncommon · Judgment · #3
Create two 1/1 white Bird creature tokens with flying.
Flashback—Tap three untapped white creatures you control. (You may cast this card from your graveyard for its flashback cost. Then exile it.)
Legal inCommanderModernLegacyVintagePauper
Not legal inBrawlStandardPioneer
7 printings · $0.49 to $49.99 at Card Kingdom
| Set | Number | Rarity | Card Kingdom | Foil |
|---|---|---|---|---|
| Commander Masters | 17 | Common | $0.79 | $0.99 |
| Dominaria Remastered | 2 | Uncommon | $0.59 | $0.79 |
| Judgment | 3 | Uncommon | $1.79 | $49.99 |
| Modern Horizons | 4 | Uncommon | $0.59 | $1.49 |
| March of the Machine Commander | 174 | Uncommon | $0.49 | — |
| Phyrexia: All Will Be One Commander | 59 | Uncommon | $0.59 | — |
| The List | JUD-3 | Uncommon | $0.59 | — |
7 rulings from Wizards of the Coast
- 19 March 2021You must still follow any timing restrictions and permissions, including those based on the card's type. For instance, you can cast a sorcery using flashback only when you could normally cast a sorcery.
- 19 March 2021If a card with flashback is put into your graveyard during your turn, you can cast it if it's legal to do so before any other player can take any actions.
- 19 March 2021“Flashback [cost]” means “You may cast this card from your graveyard by paying [cost] rather than paying its mana cost” and “If the flashback cost was paid, exile this card instead of putting it anywhere else any time it would leave the stack.”
- 19 March 2021A spell cast using flashback will always be exiled afterward, whether it resolves, is countered, or leaves the stack in some other way.
- 19 March 2021You can cast a spell using flashback even if it was somehow put into your graveyard without having been cast.
- 19 March 2021To determine the total cost of a spell, start with the mana cost or alternative cost (such as a flashback cost) you're paying, add any cost increases, then apply any cost reductions. The mana value of the spell is determined only by its mana cost, no matter what the total cost to cast the spell was.
- 8 December 2022You can tap any untapped white creatures you control to pay for Battle Screech’s flashback cost, even ones you haven’t controlled continuously since the beginning of your most recent turn.