If anyone is planning on travelling to Nepal, you might want to contact
Festival of Asia, 1-800-533-9953 travel agency.
They are very friendly, professional, patient, and will try their best to get you the cheapest air tickets. This is not my company or anyone that I know of's, so I am not trying to promote my personal business.
I am planning to visit Nepal, and I had previously called many travel agencies, owned by Nepalese and also Indias. From my experience I found them very unpleasant, lazy, and unreliable. Very often they said they would call me back after having more info, but they never did.

So finally I fell on Festival of Asia, travel agency. And there I found the best deal, and great customer service.