One thing I learned at the Florida Authors and Publishers Conference this past August was that Barnes and Noble is now considering taking Independent author's books on their shelves.
There are a couple things you must have. One is to have the your book with Ingram or another distributor where there is a returnability. Kindle Direct Publishing (Amazon) does not. Second you must have the price printed in the barcode. Third you must bring a sell sheet to the B&N with you when you go to talk to the them. The sell sheet template can be found on line and contains the front cover of you book, a brief synopsis, all the details of your publisher, formats, availability sources, and your bio.
If you don't have the price in the barcode you can purchase a barcode from Bowker or if you buy your ISBNs you can manage them there.
Sometimes I make horrible mistakes because I don't know any better. I've been in the business for 14 years now and still don't know it all. the rules are changing all the time and it's hard to keep up.
Last week I tried to put new barcodes including the prices on two of my books. I was so proud of my self when I did it. when I received the digital proofs back from Ingram I realized that I had put the wrong prices on the wrong books. Shoot me now please. Since each barcode cost $25 and ingram charges $25 for each change I felt really discouraged. I'll have to wait for payday to fix it. Oh well, another lesson learned.