Excel SKU Reconciliation & Deduplication

I need an experienced Excel data specialist to tidy up my product master. The May 20th workbook is the baseline; the current workbook must be compared against it, SKU-by-SKU, using each COSKU’s unique ID to pinpoint anything my CSRs have added since that date... (Budget: $30 - $250 USD, Jobs: Data Analysis, Data Cleansing, Data Entry, Data Management, Data Processing, Excel, Excel VBA, Visual Basic)