Here are some of the domestic flights operated in Nepal with an estimated price:
Kathamdu - Pokhara : 120USD
Kathamdu - Lukla : 175USD
Kathamdu - Bharatpur : 110USD
Kathamdu - Bhairawa : 140USD
Kathamdu - Nepalgunj : 150USD
Kathamdu - Biratnagar : 150USD
Kathamdu - Simara : 100USD
Kathamdu - Bhadrapur : 185USD
Kathamdu - Janakpur : 120USD
Pokhara - Kathmandu : 120USD
Pokhara - Jomson : 125USD
Pokhara - Bharatpur : 80USD
Pokhara - Bhairawa : 90USD