book_buying.xml

<abilities>
  <ability>
    <name>Book Buying</name>
    <key>book_buying</key>
    <skill>reading</skill>
    <icon>reading_11</icon>
    <description>
      Book prices are reduced by 50%.
    </description>
    <type>passive</type>
    <passiveInfo>
      <modifiers>
        <modifiers>
          <type>ReadingBookPriceReduction</type>
          <amount>0.5</amount>
        </modifiers>
      </modifiers>
    </passiveInfo>
    <unlockInfo>
      <autoDiscover>0</autoDiscover>
      <unlockRequirements>
        <requiredLevel>4</requiredLevel>
        <requiredPoints>2</requiredPoints>
      </unlockRequirements>
    </unlockInfo>
  </ability>
</abilities>