Errors on internet

One day, I was on ecampus.com website. I wanted to sell Diseases of the Human Body book to ecampus. After entering in all information about the book that was required, the computer generated some number that was suppose to be the price that ecampus was willing to pay for my book. As it turned out, my used textbook was worth $1,000 dollars. I was doubtful. I erased the information, and then entered the information again. To my suprise again, Ecampus was willing to pay $1,000 for my used textbook if I send the book to them by mail. I was still doubtful. I emailed the online representative and ask them, "Why are you willing buy the book for a price so high?" The representative emailed me back and said, "We are sorry. It was computer error." As it turned out, Ecampus was willing to buy my book for a lot less.