eBay Integration for WooCommerce

Hi support,

Our site is a multivendor Store where different people can sell their products.
We also want the functionality which allows the sellers to connect their eBay account with their dashboard.

The requirements are simple.

1. Sellers should be able to sync their WooCommerce products with their eBay account.
2. A Seller should be able to import their eBay products into our store.
3. If they make some changes to a product (Like price and description) on the web store then it should also be changed on eBay.
4. If someone buys a product on eBay then the product Stock quantity should be decreased on the web store and if someone buys a product on the store then the quantity should be decreased on eBay.
5. The product Import Export and sync process should be fast.
6. Every Vendor should be able to manage their own Wocommerce and eBay products Individually and simultaneously.

Let us know if it can be achieved and if it needs the custom development then what will be the time and total cost?

Thanks