Background: Female gets married, has two children, gets divorced (keeps the house), writes a revocable Living Trust with the children as beneficiaries, then dies in 2012 while the children are minors. The house goes into the trust (now irrevocable) and the ex-husband moves into the house to care for the children.

Question: The children, now adults, want to sell the house ($1.1M). The house is still in the trust. What is their basis? The original purchase price ($400k), the value when their mother died ($740k), or something else?