I don't know the cost... but I do know that parsing xml and outputting excel is not all that sophisticated. However you'll need a more concrete application of the process to get some bytes built. Hit craigslist software developers up for some quotes to get a better idea of what you need to move forward (dont hire anyone yet!). And start reading: http://www.xml.com/pub/a/2005/11/09/rexml-processing-xml-in-...

Good luck.