In Coolidge Corner, down the street from the Barnes and Noble, there is a seemingly independently owned bookstore called Brookline Booksmith. Its selection is not much different from a national chain such and B&N or Borders, but down the stairs there is a used book/video rental store that is willing to buy your used books. Be ready to be turned down though, because what they buy depends a lot on what cashier receives you. Also, if your book is underlined or highlighted, they will not buy it.
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