Is eBay plagued by fraudsters and what can be done to prevent scams/wasting sellers' time?

[sylviavo11]

I have tried to sell a dress on eBay three times. First time, it didn't sell. Second time the "buyer" turned out to be someone who had hacked another user's account and was trying to access my personal information. eBay informed me of the scam only after I'dcancelled  it myself and reneged on the sale. The third time, my dress sold for $295 but communication has been the sane as the last sale, leading me to believe it is again a scam. I have not heard from eBay so am now left frustrated and without any profit from my dress, which I really wanted to sell Quickly. Has this happened often to anyone else? It really puts me off.