online trading is all about trust.
if u dun trust each other, then dun trade lor..
juz buy from a local store would do..

as simple as that 

PS - lelong oso got so many scam and con case, even they got ic validate feature

Most common attitude in human is GREED. Fraud and scams usually happens when the human itself are too greed and fall into the trap of the conmen when he/she attracted with the cheap price that conmen offer. Yup, people should do more research and survey before dealing with online trading. If everyone should do so, there wouldn't have scam cases..