Eddie Sefko, Mavericks insider for The Dallas Morning News, answered questions during an online chat with readers Monday afternoon. Here are some of the highlights:Question: What's your biggest concern about the Harrison Barnes signing?Sefko: "I'm just a little concerned that they might have overpaid. OK, a lot concerned. The Mavericks' hope is that Barnes will prosper now that he's out of the shadow of Curry and Thompson.