Mm-hmm... and yes, those three IDs, efortown, kobook and city-walk (the three sellers selling the same item) are the same person. In itself not a problem, of course, because there is nothing against having different selling IDs for different products - but given that all three are used for selling the same item, it conveys the impression that this seller is trying for a monopoly.
Note too that the item is listed as being in Kagurah, NSW (Australia) but the seller is registered in China. (My guess is that the item location is false.)
Also of interest is that under the city-walk ID, one of the replies by the seller to an unhappy negative is "buyer promise change it after refund, we did refund, but buyer don't change it". If the item "Not worked and burned the system" (as the negative comment says), the buyer SHOULD receive a refund, and the seller is air-dreaming if he/she thinks that even with a refund that translates to a positive purchase experience for the poor buyer who no doubt has to sell out additional money to fix his/her system.