To buy: $50, IKEA.com. To buy: $249, ikea.com. To buy: From $249, ikea.com. She notes that while the basic design has stayed pretty much the same, the BILLY has gotten some updates over the years, including the new bright yellow version, above, launched in celebration of the bookcase’s 40th birthday this year. To buy: $60, ikea.com. To buy: Launching in 2020 To buy: Launching May 2020