Cant help on price but using a good vacume to get most of the dust up then wipe over well rinced cloth,soapy water will do for general dust have some solvent for the bathroom just in case of silicon marks
I always use some old scrim cloths to polish suff up afterwards .
You might need to post more info the house to get help with the pricing how many bathrooms and shower doors how many windows to clean etc. What state the house is in as builders vary in how they keep a property as they work on it .
Hope it helps and good luck
Rob