Linked data table

[Thanksinadvance]

Hi,

Hoping that someone can please help, have been trying to solve this for 2 days and am almost done with it.

I've basically linked the Value (Price x Qty) of 2 items in a Single Variable Data Table each. What I'm hoping to do is to see the Change in Value when I change the price of each item (so that a change in Item A is reflected in Item A+B). Have almost everything completed but am not sure why the 'correct' value only turns up in the last value of the data table!

Am extremely frustrated and really hope someone can help.

Thank you for any help provided!