Is there a better alternative to grouped rows?

My team has an excel sheet for estimating project costs. It's a list of ~4,000 physical items with corresponding prices. Each item incurrs different ammounts of labor time from different departments. The users go through and build a shopping list by entering quantities into the sheet. The direct and indirect costs are then summed.

The Problem: The sheet has 8 layers of grouped rows. Expanding all of them makes it crash. Collapsing a group in the first layer doesn't collapse any children. We need to use a macro to reset all the grouped rows to original state. The whole thing is formatted as one big table so users can filter for the parts they selected. I suspect that this and all the conditional formatting slow it down.

Is there a cleaner way to accomplish this kind of task? My gold standard would be something like the RockAuto website with its well formatted collapsed list and separate shopping cart. Is there a more modern alternative to grouped rows? Maybe I would benefit from hiding some of the data in a separate lookup table to reduce the size of the grouped list.

I want this to be a web app with a database, but we don't have the money or talent right now.