Below is how you can see how big the dick that f***s you will be:
1. Navigate to FBA Inventory Page and go ahead and filter out the Oversize and Extra-large items since those don't apply.
2. Sort by the highlighted column below.
Do NOT pay attention to "Inventory Level" column - this is pointless and not true.
Once you sort, you will notice some items have red text (19.2 below) and some do not. The items without red text are either (1) oversize of (2) listed in the last 180 days. The NON RED items do not incur the fees.
3. To see the low inventory fee per unit, you need to scroll to the right and click the highlighted part below. You will then see the fee per unit. You will pay this fee on EVERY unit you sell of that item until the next reset date (which is every Sunday around midnight PST).
Could Amazon have made a better report for this? Sure, but why? lol.