Simple script to fetch OSRS GE data from their wiki pages.

OSRSGEDataFetch.js

// Run on a OSRS GE wiki page such as: http://2007.runescape.wikia.com/wiki/Exchange:Abyssal_whip

var prices = jQuery('[data-data]').attr('data-data').split('|'), thisprice, data = [], volumes = [], isSmall = false;

// This loop has been 'borrowed' from their implementation of Highcharts.
// http://2007.runescape.wikia.com/index.php?title=MediaWiki:Common.js/GECharts.js&action=raw&ctype=text/javascript&reviewed=1487971769
for (var i = 0; i < prices.length; i++ ) {
    if ( prices[i].trim() ) {
        thisprice = prices[i].split( ':' );

        data.push( {
            // time
            time: new Date(parseInt( thisprice[0], 10 ) * 1000),
            // @todo should this be parseInt?
            // price
            price: parseFloat( thisprice[1], 10 )
        } );

        if ( thisprice[2] && !isSmall ) {
            volumes.push( [
                // time
                parseInt( thisprice[0], 10 ) * 1000,
                // volume
                // volumes are in millions
                parseFloat( thisprice[2], 10 ) * 1000000
            ] );
        }
    }
}

console.log(data);