Cheapest priced copy (Adventures in the Forgotten Realms): $2.99 at Card Kingdom, near mint, their price list as of .
Oswald Fiddlebender 
Legendary Creature — Gnome Artificer · 2/2 · Rare · Adventures in the Forgotten Realms · #304
Magical Tinkering — {W}, {T}, Sacrifice an artifact: Search your library for an artifact card with mana value equal to 1 plus the sacrificed artifact's mana value, put it onto the battlefield, then shuffle. Activate only as a sorcery.
Legal inCommanderPioneerModernLegacyVintage
Not legal inBrawlStandardPauper
5 printings · $2.99 to $99.99 at Card Kingdom
| Set | Number | Rarity | Card Kingdom | Foil |
|---|---|---|---|---|
| Adventures in the Forgotten Realms | 28 | Rare | $2.99 | $5.99Out of stock |
| Adventures in the Forgotten Realms | 304 | Rare | $3.49 | $4.99 |
| Adventures in the Forgotten Realms Promos | 28a | Rare | — | $99.99 |
| Adventures in the Forgotten Realms Promos | 28p | Rare | $6.99 | $16.99 |
| Adventures in the Forgotten Realms Promos | 28s | Rare | — | $7.49Out of stock |
3 rulings from Wizards of the Coast
- 23 July 2021An artifact's mana value is determined solely by the mana symbols printed in its upper right corner (unless that artifact is copying something else; see below). If its mana cost includes {X}, X is considered to be 0. If it has no mana symbols in its upper right corner (because it's an animated land that's also an artifact, for example), its mana value is 0. Ignore any alternative costs or additional costs (such as kicker) paid when the artifact spell was cast.
- 23 July 2021A token has a mana value of 0 unless it's copying something else.
- 23 July 2021If an artifact is copying something else, its mana value is the mana value of whatever it's copying.