My lovely sister-in-law suggested giving a money tree to my parents as a gift for their 50th wedding anniversary. This would be a gift given by three siblings and the grandchildren. What is a proper amount to give for such an occasion. p.s. only one sibling is helping financially pay for the anniversary celebration which is quite large, no one else "had the money to contribute". I am looking for an honest and precise dollar amount to deliver back to her. Thank u!