I'm not really familiar with this bag in terms of authenticity, but it was a style that wasn't too popular and I think the likelihood of it being inauthentic is slim. I see that the tag has the black string still attached and what looks like a Neiman Marcus tag.
Do you happen to have more pictures? It's hard to tell from that angle.
black quilted hobo will be more useful i think
I'm not really familiar with this bag in terms of authenticity, but it was a style that wasn't too popular and I think the likelihood of it being inauthentic is slim.