Including real prices and a cost per day to travel in Vietna, i would say Vietnam is one the cheapest place in the World for travelling and living as well.
To Book Cheap Transport In Vietnam: Hanoi Journey car rental is a good option
How Cheap Is Vietnam?
How Much Does It Cost To Travel In Hanoi, Vietnam?
Day One – Hanoi
Previous to arriving in Vietnam You can purchase a Visa approval letter online for $17.00 / 385000 VND – Linked is the same company I purchased through and I had no issues at the airport.
While going through immigration I had to buy my Vietnam Visa stamp which cost $25.00 / 565000 VND.
Then James and I split a taxi we had prebooked from the airport to Chien Hostel $8.80 / 200000 VND.
Craving western food for dinner I grab mac n cheese, fries and a soft drink from S&L’s Diner costing $6.60 / 150000 VND.
We stay in a large dorm room at Chien Hostel which includes breakfast. It costs $5.05 / 115000 VND per night
Daily Cost In Vietnam: $62.45 / 1415000 VND
cited from Backpackerswanderlust