Welding Jar Welding Jar gets the top spot for me because it is cheap, efficient, and far more versatile than a zero-mana uncommon Artifact has any right to be
Sudowoodo #110 (Pokemon Lost Thunder | Pokemon Cards) prices are based on the historic sales
[W] Split Spiral Punch: 30Your opponents Active Pokmon is now Confused.[W][C][C][C] Resonance: 120+If your opponents Active Pokmon is Confused, this attack does 120 more damage.weakness: [L]2resistance:retreat: 3
Copies in better condition and scarcer finishes generally sell for more
Whenever an artifact an opponent controls is put into a graveyard from the battlefield, this creature deals 1 damage to that player
Ultimately, the limited print runs, themed designs, and collector demand create the perfect storm for these cards to increase in value