Personally I never buy stuff from e-bay. Don't care what the savings. Buy it from a reputable vendor and if there is a problem they will take care of it. As far as it being as bad as the single chain that's not entirely true. I've got over 500 miles or more on my pocket bike dual chain with no problems. As I stated before, its all in the experience and understanding of a part as to how it performs. Most people ran into a problem or their chains stretched and they tossed it for a belt drive, well belt drives stretch too and loads of other problems. Especially when you go up hills. I'm not a sales man for either one. I can only speak from experience and these are solid gear boxes although you will get a bad egg(same with engines) every now and then. They are chinese made after all, though just about every small engine bike/pocket rocket/atv uses them so I don't understand why they have gotten a bad rep, chalk it up to inexperience is what I think.