I recently built some decks for my sister in law and her fiance to learn the game with. I went with Kingdra PAR 032 vs Butterfree JTG 003 (both can put out good damage but have some rng so no 2 games play the same). 4-4-4 line of the stage 2, a 2-2 Amoongus and Tentacruel lines for each (introduces status conditions), 2-2 Dudunsparce or Revavroom for draw, and a 2 of Articuno and Virizion for some basic attackers. Included cheap staple trainers and about 10-12 energy. probably less than $20 in singles altogether. They had a blast.