There are many (consignment) sites that sell authentic (vintage) Chanel bags, you can try these:
http://www.designer-vault.com/collections/chanel-bag?page=3
https://www.therealreal.com/
https://www.yoogiscloset.com/latest-arrivals
http://www.malleries.com/
http://www.coutureusa.com/m-2-chanel.aspx
http://www.fashionphile.com/
http://www.annsfabulousfinds.com/
There are many more, but you should be able to find something you love on one of these sites. They are pretty reputable.
You can also try Ebay and Tradesy, but please have the bag authenticated first.
Thank you for the reply.I saw one online it's called boutique patina.Do you guys think it's safe to buy from that company?
Thank youBoutique Patina is a reputable seller. Never purchased from them but I know members here have and have got good things to say about the company and owner.