I have bought over 100 items on E bay and every transaction bar one has been without a problem. The only one with a problem was when a guy was selling for the first time and did not use very good packaging. He was very embarrassed when I contacted him. It can be quite exciting watching the clock and the different bids occurring.
Have you ever sold anything on there?
Do you know anyone who does really well on there?
I have not sold on there yet,so what problems are out there?
Generally had positive experiences, both selling and buying. 99% of people who I've dealt with are fine. Its when you get a chancer/scammer/idiot or a combo of all three, that's when problems can occur.
The casual chancers generally aren't too bright or original. EBay is heavily weighted in favour of the buyer, so getting any the description 110% correct is essential. Don't leave nothing to chance by understating or overstating the condition of anything you may be selling. Having said that, I've had a couple of occasions when a previously mentioned idiot has complained about a blemish or fault that was clearly stated - One was an old Nokia N95 I was selling for purely scrap or spares. The bloke emailed me to say it wouldn't switch on despite being fully charged!
The most frustrating thing with eBay imo is getting unjustified feedback removed. Basically you can't unless you go down the road of filing an eBay defamation report (logistical nightmare) its virtually impossible. Good feedback can be at the mercy of the chancers and idiots unless it can be proven they are pulling a scam. Whilst I've only had to deal with those situations about three times over the years, neverless its hassle nobody needs.
For items of even moderate value, sending the goods by recorded or tracked delivery is vital. Whilst most people are honest, there's still a few chancers who will try the "I haven't received my item and want a refund" trick. High value items, I always send special delivery.
Certain goods I will only ship to the UK. I make that VERY clear in the description.
As for buying: in over ten years, I've only once had to claim my money back when a CD I bought on behalf of my daughter was clearly a snide fake.
In general, most people on eBay are sound. You just have to be on your guard for those that aren't.