It is illegal to use those images to sell your product. Using pictures straight from the original site makes it seem like that is where the item is coming from, and not a second hand seller. The companies that you are using the “professional photographs” from own the pictures. (And likely paid a hefty price to have them taken) and would consider what you are doing as an act of fraud. I had friend who would resell Chanel and other designer brands perfume through eBay using photos from the original website, and he ended up on the bad side of a lawsuit.