Common: Base Set (1999) - $1 to $30
Uncommon: Base Set (1999) - $3 to $50
Rare: Base Set (1999) - $10 to $250
Holo Rare: Base Set (1999) - $50 to $400+
Reverse Holo Rare: Base Set (1999) - $30 to $300+
Full Art: XY Phantom Forces (2016) - $3 to $100+
Alternate Art: Chilling Reign (2021) - $5 to $250+
Secret Rare: Vivid Voltage (2020) - $20 to $150+
Rainbow Rare: Cosmic Eclipse (2019) - $100 to $500+
Gold Star: EX Dragon Frontiers (2006) - $150 to $1000+
It's worth noting that prices for Gengar cards can fluctuate based on market demand and supply, so their value may change over time. To obtain the most accurate pricing information, you can refer to reputable online marketplaces or consult with card collectors and dealers.