All perfect praise be to Allah, The Lord of The Worlds, and may His peace and blessings be upon our Prophet Muhammad and upon all of his family and companions.
1. If the oaths were taken on one thing or matter i.e. if a person took more than one oath (to emphasize) not to buy a certain object whether this occurred in one session or several sessions and bought it, then he is obliged to offer one expiation.
In this regard, Al-Imam As-Shrbini (May Allah have mercy on his soul) said (What means):”The combination of more than one oath taken on the same matter implies emphasis, and if they were broken, then one expiation is due regardless of the oaths taken in this regard since they are bond with your intention on the same matter.” [Mughni Al-Muhtaj vol.4 pp.324]
2. If the oaths were taken on more than one matter .i.e. took an oath to visit a person and another one to buy this item...etc and broke them, then an expiation is due for each broken oath. And Allah Knows Best.