Today I tried booking a Delta flight thru VA's agent. The flight is AUS-ATL-DCA with a return DCA-MSP-AUS. The told the agent the Delta metal flights that I wanted to use but he said that he didn't see any "N" class seats to book my award. He recommended I contact Delta to give me an idea which flights would have "N" class seats for the dates I wanted to fly. I've already contacted Delta via email and waiting for a response. Is there a way for me to look for these "N" class seats in the Delta website?

Also, I'm not sure if the agent is correct but he's telling me that this RT flight would cost 50,000 miles (the award chart states RT is 25,000 miles within the continental US)... does this make sense?