Chapter 2 of Matthew's Gospel tells us of the Magi's quest for the new born King of the Jews, the flight of the Holy Family into Egypt, and the return of the Holy Family to Nazareth. In this chapter we are told of the gifts that the Magi presented to the child Jesus. These gifts had a symbolic meaning, but they likely had a practical purpose as well; especially in the flight into Egypt, and in the return to Nazareth.
We don't know how many Magi there were. The word Magi is plural, so we know that there were at least two of them, but there could have been a dozen or more. Since three gifts are mentioned, traditionally we assume that there were also three Magi. We have even given names to them: Gaspar, Melchior, and Balthasar. What is certain is that there were three gifts: gold, frankincense, and myrrh.
The specific mentioning of what these three gifts were implies that their substance is important; much more important than the number or names of the ones presenting them. Gold is a gift for a King, symbolising Jesus' kingship. Frankincense is an incense used by priests, thus symbolising Jesus' priesthood. Myrrh is used in embalming the dead, which prophetically signifies that Jesus was born to die.
These are the symbolic meaning of these gifts, but they must have also had a practical purpose. It is likely that Mary saved the myrrh for Jesus' burial; although it is also likely that some of it was used for Joseph's burial as well. The Frankincense may have been used in the home of the Holy Family as they prayed, as well as being given to the Temple priests as a sacrifice, and to the leaders of the synagogue for use in the liturgy. But it is the gold that had a more pressing necessity.
Joseph was a carpenter. Not a rich profession, but one that was adequate to provide for his family quite comfortably. The gold would have made his family somewhat wealthy. It would likely be at least enough to live on for the next twelve years.
What did Joseph do with this money? The rest of chapter 2 of Matthew's Gospel makes it rather obvious. They needed it in their flight to Egypt. From Matthew's account, we get the impression that this flight was in hast; probable not allowing Joseph to retrieve his carpentry tools. In all probability, not only did Joseph have to leave his tools behind, but most of their other possessions. The Holy Family needed the gold to live on in Egypt until it was safe to return.
When they did return, it was not to Joseph home town in Judea, but to Nazareth in Galilee. Joseph may have been able to reclaim his tools, but he may have not. Having been absent for up to ten years, his tools may have gone missing. That is, if he felt it was safe enough to have gone bake to Judea for them. In any case, that rest of the gold was probably spent in buying new tools and setting up shop in Nazareth.
Gold, frankincense, and myrrh; these were the gifts. They all had a symbolic meaning, but they also had a practical significance, especially the gold.