One of the many treasures you can find
If you plan to do some buying through eBay keep in mind that as trustworthy as hard eBay works to make their platform safe, you are buying from a member, not eBay itself.
Why the distinction? You need to check out the buyers as an individual entity.
What is their feedback rating. Anything below 97% throws a big flag unless they are relatively new. In that case, one glitch will make them look pretty bad so go into their feedbacks and review the reasons.
If you see an angry one, check on the member who left it. Often you will find that they have a bad score as well because the "world" is not treating them right. If that is not the case, go back to the original seller and look at some more.
If they have a 99.+ up to 100% they are probably trying to do right, but when you are dealing with as many people as are on eBay and International as well, something can go wrong. Check the negative out and see if they gave an explanation. If you have more questions, contact the seller and ask them about it. From there go with your "gut feeling".
What are their terms on payment, shipping, returns and if something goes wrong? Do not send cash. Except for eBay Motors, where you might pay in person, they should not request cash or wire transfers. You need a payment trail should something happen. eBay will cancel the listing if they find requests for cash and continued requests will probably lead to them losing their eBay membership.
Most sales will have a refund policy. If they do not have it and you still want to buy from them, write to them and ask. Don't rush just because the auction is about to end. Do your homework.
More on buying later.