eBay inventory stock update script needed

Hi, I need help with a eBay business. The database is built on mysql, and I am keeping track of the product inventory within a mysql table. By using the eBay API, I am creating listing and keeping track of inventory if it is sold. Right now I am running API call to check if a product is sold for "buy it now (fixed)" But now that there are so many products and so many unnecessary API calls are used to check if the product is sold, I need to switch to either - eBay notification call, where I receive a call if a product is sold OR - parse the emails from eBay I receive when a product is sold OR - If you have a better recommendation, I'm open to hear about it It needs to work with the current mysql table I have created and keep track of the product inventory Please use the eBay sandbox API and the table schema I provide. It should be a plug and play script that the only thing that needs to change is the developer access key/secret key and the db username / password. If notification service is used, I would need a clear instruction how to set it up - for I have not used this specific feature before Please use php to make this happen thank you and good luck, let me know if you have any questions.