Hi there, we are a cleaning company (I've had to change my name and email due to hackergate thingy, I was 'BallsforEarrings!)
How long a clean takes depends upon variable factors such as:
How large is the home
How many bathrooms, size of kitchen (kitchens and bathrooms require the most detailed work)
Hard floors need mopping as well as vacuuming so how much expanse of hard floor as opposed to carpeted
How many live in the home and are their pets and children (heavy or light traffic areas)
How messy are the individuals, ie is the house picked up and prepared for cleaners on cleaning day or is it all left in a mess and how much clutter to work around.
Mould in bathrooms?
Will clients be home and in the way of service during clean or out all day and nobody using rooms to be cleaned.
Service level on offer, ie how detailed is their service, just the basics can be done in a couple of hours in a house that is prepared for cleaning, a more detailed service including windows and paintwork etc will take at least an hour longer. Some cleaning services have branched out into ironing but I can't advise about that as we don't include this.
Things like the above determine length of a clean and price, if your cleaning service is experienced they should be able to give a price around what they see when they come to meet you and view the house. Let them know if you want more details included at this point and then they can price the job correctly.
Service level MUST be determined at the quote otherwise, if the scope of the work alters over time but not the price the cleaning service will cancel and replace for clients where the price works for them. Cleaners are in such demand they usually run a full schedule no matter what their price needs to be to be viable and they often don't want a confrontation so will just excuse themselves and move on rather than increase the price (I know this because of my involvement with the industry!) Sad but true, communication is key for lasting relationship but many avoid these conversations.