As you maybe already found out the Microsoft chart is just a snapshot from a specific version of Dundas Charts. So if you start with these charts you can easily upgrade to the current version from Dundas, but their prices are far behind free.
Within your question you wrote you have a lot of data and it should be updated in real time you'll run into problems will nearly all the graphs out there. As far as i know the best graph component that can handle a lot of data very fast is National Instruments but these are also not cheap.
So if you really need to show a lot of data in real-time i think there is nothing out there for free.
