how much
1. How much is the cheapest flight?
2. How much does the cheapest flight cost?

Which one is correct and commonly used?

Question

how much
1. How much is the cheapest flight?
2. How much does the cheapest flight cost?

Which one is correct and commonly used?

Answer

They're both correct and equally common.

Answer

sorry i meant the 1st one that is commonly used .. :)

Answer

They both grammatical correct! 
but the 2nd one is commonly used .. ~

Answer

number one