Look for sellers with high feedback rating (97% or more) with lots of sales (over 1000 is better) i.e: Power sellers etc..
Make sure the item is shipped to Sri Lanka before you bid
Don’t go for very cheap items as there are lots of fakes, if you find a deal that is too good to be true, then most probably it is…
As I said before there are lot of fakes, especially for things like Memory cards so be careful. There are ways to spot them but it is getting difficult each day.
Don’t buy very expensive items like Cameras, high end mobile phones. Because you may have to pay tax for them at the customs, and if something goes worng with the product you have to ship it back to the seller for a replacement and can’t trust all of them to honor warranty agreements.