Quick research question for sellers actually running inventory

Roughly how many SKUs do you run?

How do you track your cost basis per SKU (spreadsheet, software, nothing)?

Have your reimbursements dropped since Amazon moved to sourcing-cost reimbursement in March 2025, and roughly by how much?

If a tool audited claims and kept cost basis in sync, would you pay a flat monthly fee, or is free/self-file or percentage-of-recovery the better fit for you?

Not selling anything, just trying to understand how people handle it now.

Thanks.