I use both eBay and Agon for sales, just depends what I am selling.
High dollar, more unique items usually will do better on Agon and of course the commission is a LOT less here, max is $150 compared to eBay which can run right up to $750! before it is capped which is disgraceful in all honesty.
Now cheaper and lesser goods, cables and similar is pretty much an even wash and I will usually list on both sites as I see a LOT of Agon sellers doing the same.
As far as buying I check both sites but extremely important is the feedback whichever site I check. I have been on eBay since 2002, here since 2012 for sales/buying and 100% feedback is my goal on every single transaction.
Yes there are a lot of misrepresenting when it comes to goods, EBay being worse imho. Its always a case of buyer beware, do your research and homework and use that very rare animal....common sense!