Update:

Thanks for your patience. I was able to touch base with our Retail Support Team and we suggest that you leave any unit costs that you don't wish to include as blank (e.g. do not enter in "0").

A bit more information on how the app is set up: if you assign a unit cost of zero, it reads that as an entry. For example, the logic works so that, if you enter "0" as the unit cost, then the system is going to read that cost as exactly "0".

Hope this helps get you where you need to be. If my answer solved your problem, would you mind marking it as "Best Answer"? That'll help the rest of the community find what they're looking for. If not, just write back, and I'll continue to help. Thanks! 🙂