Ebay listings on web site

I have a customer who uses Ebay and a website, but doesn't want to manage two inventories. It's not a good solution to just link an ebay store or ebay ID as that takes the customer away from the website and away from important product details, matched accessories, instructions, legalese, etc. Ebay is just another marketing tool for this customer and can in no way be their only online storefront. Nothing is shipped; everything is picked up, so the web site becomes an important tool after an auction. Some of these details change, and are updated with data feeds frequently, so once an auction is bid on, no changes can be made on the ebay side. Not that anyone could update each auction hourly anyway...

Is there a way maybe through a developer tool or something to grab Ebay store listings to recreate the inventory on customer website? This is actually plan B. I had originally hoped there what be some sort of import option to the ebay store, where I could dump categories and inventory from the website, process them to add relevant ebay fields and upload as .csv or synchronize inventory locations. But no luck, so I'm trying from the opposite direction.

I don't want to go the page scraper route.