If you are on a tight budget and would like to have value for your money, living in the city and spending less, you can consider lodging into a guest house.
This kind of guest houses would just offer very simple and basic services; these types of rooms, which is common among Chinese budget traveler, are managed by some large corporation which originally set up guest houses for treating visitors of their own company, but a good number of them now would open to the public. These guest houses could be found not too far from each other, all over the city and in different parts of China.
The daily rent of these guest houses in non Canton Fair period would range from US$5-10 per night. During Canton Fair period, it is $40---$66.
Most of the operators of this type of accommodation do not speak English, so you may have to deal with some communication problems. It is better if you can find some Chinese speaking friend to help you reserve the room(s) in advance.
You can find some guest hotels in the following website:
http://www.ecomeego.com/Accommodation/Guest%20House.html