Edit in JSFiddle

<p>Simple js script for price inputs.
    <ul>
        <li>Corrects, While typing.</li>
        <li>Corrects and turns input value to valid price</li>
        <li>Make value readable.</li>
    </ul>
</p>

<input class="priceBox" type="text">

$('input.priceBox').on('priceIt',function(e){
    var d=',',
        s='.',
        dd=2,
        v=$(this).val().replace(s,'').split(d),
        l=v.length;
    for(var i=0;i<l;i++)
    {
        v[i]=v[i].replace(/\D/g,'',10);
    }
    if(l>1)
    {
        v[l-1]=d+v[l-1].substr(0,dd);
    }
    v=v.join('');
    if(v.lastIndexOf(d)==0)
    {
        v="0"+v;
    }
    $(this).data('float',v.replace(d,s)).val(v.replace(/(\d)(?=(\d\d\d)+(?!\d))/g,"$1"+s));
}).on('keyup',function(e){
    $(this).trigger('priceIt');
});