Books are meant to be read and also entertain, amuse, thrill, and educate you, while keeping you company all your life - like faithful dogs. They reflect all the while your good taste and braininess. Unfortunately, they were not meant to increase in value.

Very few do. They are not bitcoins. They are like movie ticket stubs: you got your value long ago. They won't retire you to a Tahiti hammock or parachute the grandkids into Disneyland. If, however, you'd rather sell than give them away, consider the following.

A professional bookseller usually knows a book's retail value and therefore offers a percentage of that. There's no use saying, "This is a twenty-dollar book; I want twenty dollars for it." The book has to be bought at a fair, but lower price if it's to be resold.

Usually, the book's owner doesn't know its monetary value. It's okay to ask the dealer how much a book's worth, and what percentage of that he'll pay. If you have hundreds of books, however, you'll do just as well if you let the bookseller bid on the whole bunch. The bookseller is legally obliged to give honest estimates, whether buying individually or in bulk.

Faced with an average library, dealers want only the re-sellable ones. Sometimes people say, "If you want one, you must buy them all." To which, the book person can reply, "I only want this bunch here. I'll pay for them and remove the rest, but I won't pay for what I don't want."

Library owners should know what outcome they want before they invite the bookman over. Everyone wants their books removed, of course, but you might be surprised to learn what the second most frequent motive is. It's not money. No, people want to know the books are going somewhere they'll be appreciated. That's especially so when people are selling their relatives' or friends' books. It's a tender transaction and a sensitive bookseller can help soothe an otherwise sad occasion.

How does one know the bookseller is competent and fair? Personally, I trust someone who pays with business checks, PayPal, or a credit card. A Yellow Pages ad or dedicated website says the dealer is not a fly-by-night. As for pricing: different dealers pay differing amounts for different kinds of books, so comparisons are as tough as choosing cell phone plans.

I've been a bookseller for 30 years, 12 of them in a bookshop on Chestnut Hill Avenue.  In the 14 years since I closed my shop, I've made many house calls to buy books, which I then researched, photographed, catalogued, listed online and sold. Each sale required correspondence, record keeping, packing, shipping and verifying the receipt. My brown hair turned gray while I kept loving my job, but last August 10, my birthday, I decided to quit the daily drudgery of online sales. I feared the emptiness that might follow, but took my books offline anyway.

I emailed a local bookseller I've known for years, offering him a thousand good books for $1000. A week later, he replied, "Thanks, but I can't take in that many books at once. Good luck."

I tried emailing a man I've never met, who runs an interesting shop in Roxborough. He replied, "I'm sorry. I'm currently trying to get rid of my own books, keeping only those worth forty dollars or more. Good luck."

I called and wrote to another old acquaintance who runs a huge operation in Lansdale. Weeks later: "Hi Hugh. I must get 25 calls a week, every week, from people wanting to sell, or dump, loads of books on me. Right now, I'm only buying rare books, especially 19th Century or earlier."

That's it, I thought, I'm not going to call in a bunch of separate dealers to die by a thousand cuts. I started researching the smaller auction houses that might accept about 40 boxes of books worth between $15 and $100 each.

In the meantime, I called the smartest bookman I know to tell him my problem and ask what he would do in my situation. He told me that there is such a glut of books on the market that most dealers can get basic inventory for free, or in-trade, from people grateful to get rid of their books – for the usual reasons, plus the pressure from Kindles. Most booksellers nowadays will pay only for scarce, rare, scholarly or highly collectible books.

Then he suggested I let him come over and see the books. Yes, of course. We had a great talk for a couple of hours, as we always do, never mentioning the words "buy" or "sell," and then he stood up and said, "So, how much did you want for these?" A thousand, I said.

The empty bookcases seem skeletal now. Worse, I still haven't refilled the space in my heart where my identity as a bookseller – greatest job I ever had – resided.

I hope some of my story helps you when it's your turn.

Hugh Gilmore is the author of "Scenes from a Bookshop," a collection of stories based on life in his now-closed Chestnut Hill antiquarian bookshop.