Don’t underestimate the potential of this (not-so-well-marketed) metrics tool specialised in sourcing items that eBay itself offers. You can try it for free in your Seller Hub>Growth>Sourcing Guidance Tab.
These metrics come directly from eBay and -especially- if you know how to use it and where to look at, it becomes a powerful and reliable tool.
Pay attention to the seasonality, growth opportunity scores and Top combinations! “Play” with the pre-set selections to discover which items have great potential in the following days, check the average price given, and find one of your own to sell, as close to these criteria. Make sure you bring in a “unique” item or cheapest price item so you beat the competition!