systematic quotation Google sheet

I’m doing interior design and renovation, previously I will need to spend a lot of time to do my quotation, cause it has too many of listing we need to input and calculate, but now I’m looking for systematic Google sheet set up for my oncoming project quotation to save my time and avoid calculation mistake. If possible, I would like to remain my quotation design or maybe suggestions to make it much simple and easy to understand.

I have attached my current quotation set up.