Manager, as for today, can have only one static price and cost for each product. So you have to think some “ploy” in order to achieve what you want.
A few questions:
Is the standard price fixed or does it change frequently?
How is calculated the surplus on the selling price?
Is it fixed or a percentage?
Is it different for each product?
Is it different for each client?
Sales Prices depending on the Order Code like Daily, Weekly, Monthly and is different by each of the Products
Also the Purchase Prices are different by the Order Code. If we sell in “Daily” we need to buy in Daily because it is urgent. The Margin between the Order Codes are different.
Price Changes mostly twice a year - Some Increase, Some Reduce, Some remain the same. We need to update the full list containing about 500.000 lines per Brand for 4-5 Brands
This would be a highlight for me if we can work with individual pricing by each Client or Client-Groups.
I think you can reach a good result with batch create and update starting with a well structured excel file that does all the permutation you need with specific rules.
You cannot have multiple pricing tiers for the same inventory item in Manager. The program is not that sophisticated. Purchase and sales prices entered for inventory items are only shortcuts. They prefill a transaction, but can be edited.
I agree with @Joe91. If you are managing two and a half million inventory items, you will inevitably have accounting needs Manager cannot handle. Yes, the program would accept that many items, but you will need a full-blown enterprise resource planning (ERP) system. Your case of multiple pricing tiers based on order urgency is just one example.