You may have to solve this using a sales kit.
Renumber the T0025 into a Sales Kit, let's call it T0026. Set the list price for the kit as a whole.
Under T0026
-A
-B
-C
-D
When you sell a T0026 sales kit all of the items listed below it will be shown automatically on the quote, sales order and packing list. The price of the sales kit will be the only price shown. The inventory will be decremented upon shipment.
When you want to sell A or B or C or D as separate items you can put those onto their own line item in the Sales Order. Their corresponding prices will be shown.
We use Sales Kits for several items so I know this works.
Jim