It's probably been a decade since I last used them but there were two book swapping services, I used to belong to that would handle matchmaking of people who ha

It's probably been a decade since I last used them but there were two book swapping services, I used to belong to that would handle matchmaking of people who had books the other wanted and then you could print a shipping label at home if you had a printer (they were still common at the time). For small paperbacks, you could even print out the postal details on a regular sheet of paper and then wrap it around the book and tape it up, ready to be picked up by the post office. Using the media mail rate kept things reasonable, especially for standard size books.