@heartshapedknob
The last time we moved, I left one house sparkling clean and moved into a midden. It took three hours to steam the kitchen floor, cupboards covered in grease etc. Made moving day more difficult than it needed to be.
Yep this. I have bought and sold 5-6 times, and every single time I have moved into a new home, it's been either a) in decent condition, but in need of a clean and redecoration, or b) a damn shit-tip, that has needed a few 1000 spending on it to fix its flaws, to deep-clean/steam-clean it, replace broken stuff we never noticed when we viewed the property, and remove loads of rubbish left etc. No home has ever been cleaned, let alone deep cleaned.'
And whilst we have never left our home (that we sold) a shithole, and we have always left it in reasonable condition, we have certainly never thoroughly cleaned/deep-cleaned it when we sold it. I mean, this may come as a shock to some, but we actually cleaned it when we lived in it, so it didn't need much doing to it really... 
So unless you have lived in filth and squalor for the last few years @Shahlalala - you don't need to worry about deep-cleaning the house you are selling!