Two separate slicers for same column with different selections

Hello,

I am trying to create a what-if analysis where a user can select one or more products, and modify their sales price and quantity to see how this would affect revenue. However, since changing the price of a product might also affect the sales of other products, I would like to allow for a user to independently select a second group of products, modify these too with different parameters, and then create a total of the two groups. (A scenario could be that if the price of product A is lowered, some people are expected to switch to this from Product B. So while there will be an increase in the sales of Product A, the sales of Product B will decrease - would the price adjustment overall still be worth it?)

I have one big sales transaction table that contains (among others) a sales date column, a product name column, and a total price column. My idea was to duplicate the product column and add a separate slicer to the report for each to allow for the selection of two independent product groups. The issue is of course that making a selection in one slicer will also filter the other, although I was able to get them to allow different selections by setting them not to interact with each other. Similarly, by having a KPI interact with only one of the two slicers, I can get the subtotals for each group. The problem occurs when I attempt to add the two groups together to get a total - this cannot be done just by editing the interactions. My knowledge of DAX is not that great but I have tried (without the what-if parameters) things like:

Sales = 
CALCULATE(SUM(FACTS[Amount]), ALLSELECTED(FACTS[Product Column A]), ALL(FACTS[Product Column B])) 
+ CALCULATE(SUM(FACTS[Amount]), ALLSELECTED(FACTS[Product Column B]), ALL(FACTS[Product Column A]))

But this does not work. Is what I am looking for at all possible? If it requires a completely different approach, I would be more than happy to try...

Thanks in advance!