Cheapest priced copy (Modern Horizons 2): $0.35 at Card Kingdom, near mint, their price list as of .
Faithless Salvaging 
Instant · Common · Modern Horizons 2 · #122
Discard a card, then draw a card.
Rebound (If you cast this spell from your hand, exile it as it resolves. At the beginning of your next upkeep, you may cast this card from exile without paying its mana cost.)
Legal inCommanderModernLegacyVintagePauper
Not legal inBrawlStandardPioneer
3 printings · $0.35 to $0.49 at Card Kingdom
| Set | Number | Rarity | Card Kingdom | Foil |
|---|---|---|---|---|
| Modern Horizons 2 | 122 | Common | $0.35 | $0.49 |
| Modern Horizons 2 | 349 | Common | $0.35 | $0.49 |
| The List | MH2-122 | Common | $0.35 | — |
3 rulings from Wizards of the Coast
- 18 June 2021If you have no cards in hand as Faithless Salvaging resolves, you won't discard a card, but you will still draw a card.
- 18 June 2021If a spell with rebound that you cast from your hand doesn't resolve for any reason, including being countered, that spell won't resolve and none of its effects will happen, including rebound. The spell will be put into its owner's graveyard and you won't get to cast it again on your next turn.
- 18 June 2021Casting the card again due to rebound's delayed triggered ability is optional. If you choose not to cast the card, or if you can't because an effect prohibits it, the card will stay exiled. You won't get another chance to cast it on a future turn. If you do cast the card, it's put into its owner's graveyard as normal once it resolves.