Welcome to the Magix user to user forums, so not a contact for any Magix staff and confidential data, like your email address, should never be posted to a public forum like this one.
My understanding of your question is that, to qualify for an "Upgrade" price one must already own a prior, qualifying version of the software. However, why not try taking up the offer you see and so find out what the cost to you would be? You do not commit to anything until you agree to the payment being made.
Further to what Jeff said, after purchasing, you will receive an email with a link to download the installer for Xara DPX along with a serial number. Since you've already installed Xara, you just have to activate it by putting in the code, no need to reinstall. There will also be a coupon code for the Website M package for 12 months of free usage. You can use the coupon whenever you decide you want to but you have untill the end of the year to use it.