The Successful Businessman is the Sincere One (Hadith No. 1844)
Volume 3, Book 34, Number 349:
Narrated by ‘Abdullah bin ‘Umar (radiallaahu `anhu)
Allah’s Apostle (sallallaahu `alayhi wasallam) said, “Do not urge somebody to return what he has already bought (i.e. in optional sale) from another seller so as to sell him your own goods.”
This is forbidden because it harms the first seller by putting him in loss. It can lead to other evils as well, like negativity and revenge etc. One shouldn’t put someone else in loss/harm for their own good/benefit. Honesty and sincerity will put barakah in your business.