I need a developer to create a repricing/stock update software for eBay API

General information for the business: Looking for an experienced eCommerce solutions engineer and software developer with an excellent understanding of eBay API to create a software. The software will be scraping data from various eCommerce stores and will update stock and price for eBay listings.
Description of requirements/functionality: the software should be scrapping e-commerce sites and should do the following:

1. Checking for price changes every site that we have listed from
Example: if we have listed an item from a supplier to ebay.co.uk or ebay.com the software should check for price changes to this site and change them to eBay specific listing if needed.
2. Checking and update the quantity available if needed
3. The checking activity should be running automatically at least every 3 hours a day. This should be fully customizable.
4. Add manually the item to the software with specific formulas applied (profit margin etc.)
5. The software should have an option for pause repricing and quantity of a specific eBay listing (pls refer to screenshot Formula Wizard_1) .
6. When adding a formula to the new listing the software should have an option to estimate the final price on eBay (pls refer to screenshot Formula Wizard_2).