That is difficult enough to know offline, online even more difficult. At least with the better online sites you can return it easily (Amazon, Flipkart). Ebay, forget about returning anything let alone getting anything done easily.
Usually the rule with electronics used to be that if anything is going to go wrong, it will during the initial usage period not thereafter. Modern electronics mostly is the other way around, especially with some LCD's that show problems as they age. Your shiny new TV from Ebay works fine for a year and promptly goes kaput a year plus one day. What then?
Many manufacturers offer an extended warranty that can be purchased before the warranty expires which extends your warranty for an additional 2 to 3 years depending on the manufacturer. You won't be able to buy the extended warranty even if you want to, on a product that you purchased from a vendor not recognized by the manufacturer as an authorized dealer.
That's a call you'll have to take, balancing saving against risk. I have taken that risk with manufacturer warranty in a few gray market purchases but those were for products that were just not available for sale in India.
I haven't needed service for those products as yet, so can't really say.
I've seen at least a couple of posts on the forum where FM's said that the service centers refused service for gray market products even though they were willing to pay.
