Good day!
I represent a company that working on ebay integration module for Prestashop.
Cost of this module is 199€.
As the first step, we can offer you free 30 days trial for the module and then if you see it's fit your needs you can purchase a license.
The module has stock synchronization feature, possibility to import ebay orders (also via SKU mapping).
Please let me know if you will have any additional questions.