Possibly. It is entirely possible to live in Cambodia on very little, some say as low as a couple hundred dollars a month, but odds are that isn’t exactly the life you wanted when you left to embark on your adventure of living abroad. However, you can live comfortably and with less stress on much less than back home.
As with most locations, your biggest expense will be rent. The more western the digs the higher the price tag. Add air conditioning etc. and the price tag goes up even more. Same goes for food. If you eat local street food you can get a meal for a couple dollars, sit down at a restaurant and the price goes up but is still pretty reasonable. For special occasions or an indulgent splurge, there are also expensive steakhouses etc.
Cellphone minutes are very cheap as the average Cambodian relies on their cellphone more than any other medium for important news and updates, even entertainment. In-home internet and cable tv are also pretty affordable.
Electricity in Cambodia is one of the areas of your budget where it will vary greatly based on usage. Crank up the a/c and watch the bill creep up as well.
Sometimes, as a foreigner, you may run into some trouble getting local prices at the local markets. Make some Cambodian friends and ask around to make sure you are getting a fair price. If that isn’t your speed there are large western style supermarkets with set prices where you won’t have to worry about being labeled a foreigner.