Как сгруппировать узлы в xslt 1.0 по счетному полю?

Я считаю, что это должно сработать. Пожалуйста, попробуйте.

<xsl:stylesheet version="1.0" xmlns:xsl="http://www.w3.org/1999/XSL/Transform"
    xmlns:msxsl="urn:schemas-microsoft-com:xslt" exclude-result-prefixes="msxsl">
  <xsl:output method="text" />

  <xsl:param name="templateLanguage" select="'ru-ru'" />
  <xsl:param name="fallbackLanguage" select="'en-us'" />

  <xsl:key name="itemName" match="chargeSet" use="chargeName"/>

  <xsl:template match="/">
    <!-- Retrieve chargesForDisplay -->
    <xsl:variable name="chargesForDisplay">
      <xsl:apply-templates select="//charge" mode="buildForDisplay" />
    </xsl:variable>

    <root>
      <xsl:apply-templates select="msxsl:node-set($chargesForDisplay)/*" />
    </root>
  </xsl:template>

  <xsl:template match="text()" />

  <xsl:template
   match="chargeSet[generate-id(.)=generate-id(key('itemName',chargeName)[1])]">
    <xsl:variable name="matchingItems" select="key('itemName', chargeName)" />
    <xsl:value-of 
       select="concat(chargeName, ' ', sum($matchingItems/charge/price), '&#xA;')"/>
  </xsl:template>

  <xsl:template match="charge" mode="buildForDisplay">
    <chargeSet>
      <chargeName>
        <xsl:call-template name="GetLocalizedEntry">
          <!-- Pass in all KeyValuePairs with present, non-blank values-->
          <xsl:with-param name="keyValuePairs" 
             select="name/KeyValuePair[normalize-space(value)]" />
        </xsl:call-template>
      </chargeName>
      <xsl:copy-of select="." />
    </chargeSet>
  </xsl:template>

  <xsl:template name="GetLocalizedEntry">
    <xsl:param name="keyValuePairs" />

    <xsl:variable name="templateLanguageMatch" 
      select="$keyValuePairs[key = $templateLanguage]/value" />
    <xsl:variable name="fallbackLanguageMatch" 
      select="$keyValuePairs[key = $fallbackLanguage]/value" />

    <xsl:choose>
      <xsl:when test="$templateLanguageMatch">
        <xsl:value-of select="$templateLanguageMatch"/>
      </xsl:when>
      <xsl:when test="$fallbackLanguageMatch">
        <xsl:value-of select="$fallbackLanguageMatch"/>
      </xsl:when>
      <xsl:otherwise>
        <xsl:text>[NO NAME]</xsl:text>
      </xsl:otherwise>
    </xsl:choose>
  </xsl:template>
</xsl:stylesheet>

При запуске на этом входном XML (с корневым узлом и несколькими дополнительными <charges>, добавленными к вашему образцу):

<charges>
  <charge>
    <price>2</price>
    <amount>3</amount>
    <name>
      <KeyValuePair>
        <key>en-us</key>
        <value>mobile</value>
      </KeyValuePair>
    </name>
  </charge>
  <charge>
    <price>4</price>
    <amount>3</amount>
    <name>
      <KeyValuePair>
        <key>en-us</key>
        <value>mobile</value>
      </KeyValuePair>
    </name>
  </charge>
  <charge>
    <price>6</price>
    <amount>3</amount>
    <name>
      <KeyValuePair>
        <key>en-us</key>
        <value>computer</value>
      </KeyValuePair>
    </name>
  </charge>
  <charge>
    <price>8</price>
    <amount>3</amount>
    <name>
      <KeyValuePair>
        <key>en-us</key>
        <value>computer</value>
      </KeyValuePair>
    </name>
  </charge>
  <charge>
    <price>8</price>
    <amount>3</amount>
    <name>
      <KeyValuePair>
        <key>ja-jp</key>
        <value>計算機</value>
      </KeyValuePair>
    </name>
  </charge>
  <charge>
    <price>13</price>
    <amount>3</amount>
    <name>
      <KeyValuePair>
        <key>ru-ru</key>
        <value>shelf</value>
      </KeyValuePair>
    </name>
  </charge>
</charges>

Производит этот вывод:

mobile 6
computer 14
[NO NAME] 8
shelf 13