Unofficial LEGO Sets/Parts Collectors Guide - Very rare LEGO items are not exclusive to very old LEGO... even very modern LEGO can be extremely rare. For example, the 40489 Mr & Mrs
Used Set 40489 LEGO Ideas Sailboat Adventure
Lego 40489 Mr and Mrs Claus' Living Room (Rare) | eBay
Lego 40489 Mr and Mrs Claus' Living Room (Rare) | eBay