Thai Son 2 Hotel
When I was in Hanoi I stayed at this hotel and through the website Agoda, I got a standard room for $19. It is more expensive than a hostel, but its has a slightly higher quality. Since I spent several nights out touring Halong and Sapa, I had to stay in two different rooms which were more or less the same. It was clean and simple, and despite not having a window, the bed was really great. There was air conditioning and it included breakfast, the best part of the hotel. It is buffet style and serves ready-to-order dishes like eggs and pho. One of the drawbacks is that the cheaper rooms do not have elevator access.