I seen that figure and i made sure that i showed i had over that avaiable each month in all the paperwork.
Many others have done the same but as you say there is no definte proof that this is what the ECO will look for.
But imo it would be enough if accomdation and proof of a relationship were all met.
From a practical view at least this needs to be avaiable if you are both going to live at a decent level anyway.
Its not just about getting the ok from the ECO you still have to survie and for a person coming from a different culture and enviroment (ie heating, food, telephone bills etc)