I don't know about agencies- but when I checked with Qatar directly, their rate for round trip from DC-Doha-KTM varies from 1337 to 2000 in between 3rd week of May to 3rd week of June.

Another point in the deal is total time to travel- you can reach KTM within 25 hrs once you leave DC. I thought that was great too.

Good luck!

Dharan