2 and 3 star hotels in Vietnam are so cheap, we found in some cases they were the same price as staying in hostel when the cost was divided by the three of us. We stayed at Home Hotel (thanks to Trip Advisors recommendation)
We paid 360,000VD/ $24 for a triple room with our own bathroom (120,000VD/ $8 pp/pn) The hotel was a great location, the staff were extremely friendly and let us check is at 9am when we arrive. Breakfast was included (omelette with toast or pancakes, both served with tea or juice)
The only downfall was that the hotel had no lift and we had a room on the 4th floor.