People complain a lot about there being a second Death Star. But if you think about it, it's actually pretty ingenious on Sheev's part.
He was looking for one last ditch trap to lure the rebel fleet out of hiding. A Death Star was the perfect bait, as the rebels have already dealt with it. If it were any other threath the rebels may have a) put enough planning into it and discovered it was a trap, or b) deemed it too risky and not have bothered. But another Death Star? They were probably thinking "yeah, we got this" and jumped right in without noticing anything fishy about the situation.