This is such an open ended question because it doesn't define what her "paying for it" entails. Prison? Fines? She'll have to carry it with her forever and will get bashed over the head with it if she runs in 2016, she's paying for it. She certainly does deserve some blame but it shouldn't negate her otherwise stellar service.
Hillary Clinton will pay for the Benghazi incident only when the government decides they need someone to take the fall for it. Just like anything else that goes wrong in our system, she will be held personally responsible, instead of addressing the institutional problems that allow things like this to occur.
I doubt that the U.S government goes too deep into this investigation. With her last teary eyed statement, I'm sure Hilary Clinton convinced enough people that what happened was an unavoidable terrorist attack. I think the Obama Administration will want to downplay any wrongdoing, and that will lead to it quietly dying.
No, Hillary Clinton will not pay for Benghazi and she shouldn't. What happened in Benghazi was a terrible terrorist attack. It's also more complicated then the 24-hours news cycle makes it out to be. The people who work in our embassies overseas have a unique job in spreading American ideas in hostile territories. They understand the risks they are taking. Hillary Clinton has done a solid job being Secretary of State and though she does have some blame in the attack, she does not need to be crucified for it. People forget that Secretary Rice under President Bush did not act on our intelligence when they presented her with information concerning certain attacks aimed at the United States.