A Birdramon card numbered 21 appears in the Digimon 1999 Upper Deck Exclusive Preview set and is classified with Unknown rarity (#23). Collectors view the card as an early promotional piece for the Digimon TCG era, relevant for completing preview or vintage Upper Deck runs. Current market listings show a value of $0.00, indicating scarce sales data or unpriced status rather than confirmed worth. Condition and grading would be decisive for any future valuation.