Budget Stuff

Ha Noi rental rates are below TP HCM. Typically renting an apartment means you will two months security deposit PLUS first months rent.

Then you have to add water, electricity, garbage pick-up, management fees, etc.

Bottled gas is often used for cooking unless you can survive with a microwave. A VND400,000  bottle of gas might last a single used 6 months. Using an electric kettle is cheaper than water heated by gas.

Food is a bit dependent on you and your needs. budget $5/day for street food. At least beer is cheap in Ha Noi with many micro-breweries.

Ha Noi is a temperate zone so make sure your place has decent heating.

There might be accommodation CraigsList VietNam although my experience most use Foreigner web sites.

I personally consider 600 USD the absolute minimum. Especially foreigners paying almost for everything higher prices. You also might consider, to have a bit on side for medical, transportation and finally returning home.

Well,to a foreigner, u need around 1,000USD to live in Hanoi, 500USD is for renting an apartment in downtown n 500USD is for foods n entertainment. But make sure you know how to spend money economically. Ask for price & bargain before you decide to buy anything.
Hve fun in VN!