It's true that Joseph is called a tektonos in Matthew 13:55, but the Greek word tekton simply means "craftsman" and does not connote anything with regard to level, skill, or income, and the rendering "master craftsman" is not etymologically supportable. The scanty biblical evidence indicates that the Holy Family was poor, not middle-class, certainly not affluent.
When eight days were completed for his circumcision, he was named Jesus, the name given him by the angel before he was born. When the days were completed for their purification [40 days (Lev. 12:2-8)] according to the law of Moses, they [Mary and Joseph] took him up to Jerusalem to present him to the Lord, just as it is written in the law of the Lord, "Every male that opens the womb shall be consecrated to the Lord," and to offer the sacrifice of 'a pair of turtle doves or two young pigeons,' in accordance with the dictate in the law of the Lord. (2:22-24)
This passage suggests that Mary and Joseph were poor. According to the Mosaic law the mother had to purchase and have sacrificed in the Temple a young lamb as a burnt offering and a turtle dove as a sin offering (this being done to expiate ritual impurity related to blood and childbirth, not personal sin). If the parents were too poor to afford the lamb, they were allowed to substitute two turtle doves or pigeons (Lv 12:8).
Other than this brief glimpse at the Holy Family's financial circumstances, the Bible tells us very little about their economic status. While it's true that the three Magi offered Jesus expensive gifts of gold, frankincense, and myrrh (Mt 2:11), there's no biblical evidence to suggest that they kept these items.