the question isn't the mag price, it's whether or not you can get the DAZ upgrade price to C7Pro.
It would seem to me that DAZ would by foolish to not allow upgrade. Money is money, especially in these times. They're not really out anything as I'm sure most that buy the mag version for cheap wouldn't buy C7 full price anyway.

Humankind has not woven the web of life. We are but one thread within it.
Whatever we do to the web, we do to ourselves. All things are bound together.
All things connect......Chief Seattle, 1854