This engine uses the following search URL:
https://www.ebay.de/sch/i.html?_nkw={searchTerms}&LH_BIN=1&_sop=10&rt=nc&LH_ItemCondition=7000
To add it, you need to enable the separate search bar in Firefox. It will then offer an option Add “eBay.de Sofort-Kaufen neu eingestellt defekt”.
