Most positive reviews for a forex product on eBay only really mean that the product was delivered and initially worked. You don't get to test if for 60 days and then give it a bad review if it wipes out your account.
Be careful of MT4 statistics sites. Some allow data to be tampered with or "filtered". Ask for investor access to a LIVE account buying the system. If they are afraid you'll copy trades, ask them to let you check it on the weekend and they can change the password on Sunday afternoon. Tell them to submit it to the FPA's Performance Testing if it's really that good.
if it sounds to good to be true, it is. The best traders in the world do not share what they do, why would they? There are some honest folks out there, but for the most part it is all crap. Just look at the list right here at FPA.
I would never buy any trading system from e-bay.
You can fake any results, anywhere. Myfxbook is not rock solid proof. Also, if anyone ever promises you any return, they are lying. How can you promise a return and then at the end of the page is the disclaimer of past results do not guarantee future results?