GQuuuuuuX (Omega Psycommu).

What moves the price of this card

The GQuuuuuuX (Omega Psycommu) on this page is the Holofoil printing from Dual Impact, and it trades at $2.25 in near mint condition. The same name is on 8 other printings: Dual Impact GD02-038 at $439.51, Gundam Promotional Cards ST06-002 at $78.04, Steel Requiem GD03-034 at $40.19, Starter Deck 06: Clan Unity ST06-001 at $37.08, Dual Impact GD02-038 at $23.35, Starter Deck 06: Clan Unity ST06-002 at $9.63, Steel Requiem GD03-034 at $8.40, Gundam Promotional Cards ST06-001 at $1.03, so read the set, the number and the rarity together before comparing prices.

Condition does most of the work below the surface. A copy with soft corners or a print line off centre trades well under the market price shown here, and a copy clean enough to grade trades well above it. Before you value your own copy, look at the corners under a light and check the centring on the back, where most cards give themselves away.