We did this for our upcoming trip in August.
For a value resort you would get the QSDP which is $34.99 per person per night
The DxDP is $85.52 per person per night.
In order to upgrade from QSDP to DxDP it is $50.53 per person per night.
So on my trip it is costing me $808.48 to upgrade (8 nights x 50.53 per night x 2 people)