Conditional logic for piped text

I have a constant sum question asking the number of times a respondent has bought each of the following products. In the following question, I currently pipe in the highest response via "Please rate your satisfaction with ${q://QID108/ChoiceGroup/ChoiceWithHighestValue}."

Two issues:
1. How do I break ties? e.g., someone has bought Pencils 5 times and Pens 5 times.

2. (How) can I add conditional logic? e.g., let's say I want to ask satisfaction for anyone who selects Erasers as long as purchase is > 0; if they don't select it, then the piped text reverts to the product with the highest number of purchases. Put a different way: "If Erasers > 0, then input text; else, ${q://QID108/ChoiceGroup/ChoiceWithHighestValue}."