High-net-worth or "everything" couples often have one thing in short supply: time.
Make a significant donation in their name to a cause they are visibly passionate about (animal rescue, local arts, etc.). what to buy the couple who have everything
A massive tin of high-grade Osetra caviar, a fresh white truffle (in season), or a set of single-estate olive oils. High-net-worth or "everything" couples often have one thing
A private glass-blowing class, a high-performance driving school day, or a backyard telescope session with a local astronomer. a fresh white truffle (in season)