With Opana the IR's barely went generic. The Er's are supposed to go soon. The ER's are still very expensive. Last time I checked they were about 12 bucks for the opana ER. The ironic thing is that the 10mg ir used to cost nearly as much as a 40mg ER. Now, the IR's are about 1/2 the old price. Also, don't forget that they are changing the ER formulation soon. Its supposed to be tamper resistant. The good news is that they still will make the original kind (so the rumor goes) We won't know til they come to market.