Individual flights on Orbitz will often charge through from the airline itself.

However, if you are booking such a flight, nearly always the price will be the same directly from the airline.

You may lose the portal cashback but you could easily gain it back in not having to deal with a "travel agency" if you need to make a flight change or there is some other irregular operation. Remember, unless you book directly with the airline, most of the time voluntary changes have to be processed by the "travel agency", who will add their own fees in addition to whatever the airline charges. Maybe it's worth it. But like any kind of insurance, you won't feel the pain until you need it.

(If the flight is part of a package, then the flight will typically NOT be charged directly by the airline anyway.)