Depends what you are looking for!
I would have ruled it out from the ad because if you check his feedback you can see that he had sold three other bikes in the previous week or so. Therefore he's a trader, not an original / long-term owner and therefore a higher probability of it being a stolen bike!
There are enough great second hand bikes being sold by genuine owners without taking risks on traders.
Very simple....the expression of the seller of ebay cycle will tell you the reality...you just have to concentrate or stare at him. If you find a brightness in his eyes...a bit irritation..and hurry...imagine that he is selling a stolen cycle...