I stand corrected. I didn't read far enough into the article to note that Orbital has purchased 2 Atlas V launchers while they go through the process of qualifying a new engine for Antares. I was under the assumption that they were simply fixing the problem on the existing engine and continuing to use them. I would guess they are still obligated to charge NASA at the Antares/Cygnus price level.
The shipment comes nearly one year after Orbital ATK’s last space station supply flight crashed seconds after liftoff from Wallops Island, Virginia, aboard the company’s own Antares booster. Orbital ATK engineers blame the failure on one of the Antares main engines, and officials purchased two Atlas 5 rockets from United Launch Alliance to keep the Cygnus missions flying while a new engine model is added to the Antares.
Looks like they are getting ready to try another Antares launch this time using Russian RD-181 engines:
"Orbital ATK ordered RD-181 engines from Russia’s NPO Energomash, the builder of the Atlas 5 rocket’s RD-180 engine, in the wake of a catastrophic launch failure moments after a liftoff from Virginia in October 2014. The Antares rocket crashed near the Antares launch pad, toppling two of the facility’s lightning protection towers and carving a huge crater just northeast of pad 0A’s elevated launch mount."