I found a very good deal for a new S70 and extender on eBay. The guy has good ratings and emailed me that the purchase would be "legitimate" so that I would be covered by the warranty and be eligible for tech support and updates. Why should I believe that?....Otherwise the closest official dealer is several states away from me. I'm sure the official dealer price is going to be a lot more too....What to do? Advice? thanks.