Before you purchase a DVD, or any media for that matter, check over the seller's feedback. Don't just look at the number, they could be very misleading. Alot of times, a buyer who gets a viewable DVD will state in the feedback that it was a copy, but viewable and leave a positive or neutral. This allow the feedback score to remain artifically high. Those people are just happy to get a cheap viewable DVD and don't care that its illegal or that the quality is not what it should be.
SOLUTION: Go to seller's feedback page and set it to show 200 so it'll be a faster search. Then search page for words like "copies, copy, dupe, fake". That's the only way you will know how honest your seller is. If you do receive an illegal copy, report it to Ebay (and request a refund from PayPal if you paid that way). If your research shows that the seller sells alot of bogus items, you might consider forwarding the information you've gathered to the actual copyright holder. Why? Because it's the only way to stop the illegal selling of stolen material on Ebay.
If you feel that you got a good deal, just look at it this way: The scammer purchased one CD/DVD and has copied and sold it many times over for a hefty profit. Meanwhile, if you get caught with pirated or illegally copied material, it's your fanny in the sling!
Sometimes the seller will concede to give you a refund if you return the item - Wrong! Why should you pay for shipping to return this item? If you do, at the end of it all you did get your refund, but are out the shipping cost to return it. Ask yourself: Does the police return stolen goods when the crook gets out of jail? I am currently learned all this the hard way from michaelsexcursion who sold me a set of bogus Tyler Perry DVDs. Be careful out there, it's a jungle!