At least if you could you tell me where the eshop data in php database has been stored,
I could make a script for auto exporting data to xml each time products change .
If you can do that, then it is great. The EShop products data are stored in some tables which start with #__eshop_product, you can access via database and see them easily.
From newer versions of EShop, please go to EShop -> System -> Exports, then choose to export products. You will have options to export it to XML there.
