When you move out and it's time to do the hardest task of all- end of tenancy clean up, you have to take a few things under consideration. You have to be on clear with yourself what type of cleaning is going to fit best to your needs.
A lot of the companies will give you full list, including their rates and service packages. Most of them usually have a standard plan made to meet the needs of the mass of their clients. The prices depend on different variables, like how big is the place, how many rooms does it have. These are the main criteria by whom the companies put prices on their services. In case you have decided to get your oven or refrigerator cleaned up, the cleaning company may charge you additionally. You can negotiate the price of the service over the phone in most cases. It's a good idea to have someone from the company to come on a visit before finalisation of the contract. Just to be sure, that there will be no misunderstandings later.
Having someone over could benefit you in another aspect as well. You could make them understand exactly what you need cleaned up and you could negotiate the end of tenancy cleaning prices.
The cleaning company you are hiring has to be licensed. It has to meet another legal requirements, like providing insurance for its employees.
Just remember hiring someone to perform the final cleaning work for you is something, that comes along with a few things you have to think about first.