Items Sales Report. Feature request

I introduced to a client dealing in inventory items and non inventory items in a Car wash Centre. His only problem is to be able to pull a report on the sales of Items both inventory and non inventory from Manager.

For a example a report that can say 20 quantities of Total Engine oil was sold in December and 29 items (Non inventory) of ABC non inventory item was sold in March or from January to March (Period specific).

I think this type of report will be very useful in forecasting and budgets, it can also be used for other analyses.

How possible is this feature @lubos ?