Needing macro or VBA to add child subtotal rows to a spreadsheet containing data

Hello,

I have a spreadsheet containing imported data (Sample Sheet 1) that I use to add individual costs in each cell to get a total cost for each item. This process gets cumbersome when several costs are added to the same cell. I would like to be able to easily add "child" and/or "grandchild" rows when I choose to do so in lieu of filling cells with multiple costs (sample Sheet 2).

Is it possible to have a macro or VBA that can do the following?

1. Quickly add an additional child and or grandchild row that contains formulas when I choose to add them.
2. Have the parent row subtotal the child and/or grandchild values automatically, whether there be 1 or more child/grandchild rows, without having to change the subtotal formulas in the parent row.

If any of you have a suggestion, it would be greatly appreciated! Thank you.

Thank you Richard for the VERY fast reply. So the Data...Outline...Subtotal functionality works opposite of what I'm looking for. For my scenario, I first start with a list of items that I copy and paste into a worksheet. The items copied and pasted are item no.'s and random descriptions, for example. Then I add different costs (cost 1, 2, 3...) across the row to get a total cost for each item number. The example below shows columns A, B, C, and D as imported data. Columns E, F and G are costs that are either manually input, or contain vlookup formulas to help derive the cost.
Attachment 778472

What I am hoping for is to be able to create a macro or VBA that will insert either a child row, or grandchild row, under an existing item no. when i direct it to. The added child or grandchild rows would have nested formulas in them, and the parent row (and child row if using grandchild) would subtotal everything below it, regardless if there were 3 child rows added or 15 child/ grandchild rows. The example below shows 3 items (rows 2, 9 and 14) that would be expanded with child/ grandchild items.
Attachment 778476

Thanks again for your help.

That's right Richard. Using the original 4 row example, I would place the cursor in A3, start the macro, and be prompted to add x number of rows below row 3. The added rows would contain some cells having formulas, vlookups, etc. Also row 3 would then subtotal everything that was added below it with the macro.