LEGO 21308 Adventure Time is a Ideas set valued at $111 for new and sealed sets, up 123% from an original retail price of $49.99. The set retired in January 2019 with annual appreciation averaging 9.45% since. Used copies are valued between $52 and $69 depending on condition. Secondary market prices for new and sealed sets typically fall between $76 and $121.
LEGO 21308 Adventure Time is an Ideas set released in 2017, containing 495 pieces. It builds eight brick-built characters from the series: Finn, Jake, Princess Bubblegum, Lady Rainicorn, Marceline, BMO, Ice King, and Gunter. Finn, Princess Bubblegum, Marceline, and Ice King have movable arms, and accessories include Finn’s sword, Marceline’s axe-bass, BMO’s joysticks, and Ice King’s translucent-blue stars. The set was designed by fan builder Ludovic Piraud and is based on the Brick-built Adventure Time figures project by aBetterMonkey.
A new and sealed Adventure Time is currently valued at around $111, with annual growth of approximately 6%. The average used price is $57 for those in good overall condition. Based on current trends, this set could be valued near $122 within the next year. New and sealed listings currently range from $87 to $149. The set was available for 25 months, from December 2016 to January 2019.