Write a script that can prepare Amazon uploads -3

As to the project, this is how I would like the workflow to go: I want to buy a script that does this. 1. I will prepare a list with 100,000 parts every week. This will include part number, condition, prices, quantity available, and some description. I can include pictures or links to pictures if you wish. The script will have to prepare 3 csv files for Amazon. 2. If there is an existing listing for this already in our inventory, adjust the price and quantity accordingly. (We will have downloaded a price and quantity price file from Amazon to assist this.) 3. If we do not have this listed; B. Check for an existing ASIN that exactly matches the product and list against that. (Pay attention; this step is hard. Your script will have to search Amazon for a matching listing. I will not provide ASIN or UPC or model number for this part.) C. Only if there is no ASIN, we create a new listing. C1. New and used and refurbished items all go on the same ASIN. 4. If one week I send a list that does not have a part that was included on last week's list, we have to remove it from our inventory. I prefer this be done on Google Sheets, or at least a web app of some kind, but not of utmost importance. Time is of the essence after my last three freelancers could not complete! Aaron