merging data based on sheet name using combobox from userform

Hi
I need merging duplicates items based on column D for QTY in column E and show price average for column F and show in listbox based on selected sheet from combobox1 except STOCK sheet will show as in sheet without any price average with ignore the others columns from showing in listbox .each sheet should merging alone for duplicates items.

when select sheet should from combobox1 should merge the QTY and show average price to unit price column and QTY* UNIT PRICE in listbox for instance as in picture 1 for case1 in last sheet.
and if the combobox1 is empty then will create names headers based on sheets names and show QTY every sheet after merge and the column QTY in listbox will calculate across sheets like this STOCK+BBR-BMTR+VSR-STR , and the BALANCE column = QTY column * UNIT PRICE column but when create unit price should be average price based on two sheets together STOCK,BBR when merge the ID .result when combobox1 is empty as in case2 for picture2 in last sheet.
when matching ID for all of sheets will be in the same location except STOCK sheet,please be careful.
also psted here
https://www.mrexcel.com/board/thread...bobox.1251982/