I need some ideas on how to put this system together, Please let me know which method is best to achieve the end result I want.


Data I Have:
- In-store daily sales log
- Online daily sales log
- Inventory quantity

Analysis/Actions I want:
- Sales log entry auto deducts from inventory quantity
- Average, min, max price for each item
- Suggested sales price when entering sales entry
- Statistics of sales history

Methods:
1. Excel Using SumProduct Formula (High amount of formulas result in 3-5 min save/refresh times)
2. Excel Using PivotTable (Better than sumproduct but still taking 1-2 min)
3. Excel Using Macro
4. Excel & Access Data Linking
5. Whole Thing Running In Access
6. Other


Which method will optimize a high volume of formulas that need to be calculated?