6 cubic metres doesn't seem a great deal of water to me. Let's try to visualise it:
A smallish single bedroom (of the size that many people would use as a 'guest room') might be 4m by 3m. Try to imagine that bedroom (with a suitably watertight floor!) flooded to around knee height (about 0.5m). That's how much water you've used in a month for baths/showers, flushing the toilet, in the washing machine, in the dishwasher (if any), for cooking and drinking., for cleaning the house, etc.
Scoob101 seems to be paying quite a high price for water. The standard tariff with Anglia Water is just a shade over �2.50 per cubic metre. (That's arrived at by adding together the water and sewerage charges):
http://www.anglianwater.co.uk/index.php?sectio nid=35&parentid=14&contentid=61&pager=1#ptop
They also offer a 'SoLow' tariff, which is intended for very light users of water. The criterion for qualifying for this tariff is consumption of less than 75 cubic metres of water per year (which equates to 6� cubic metres per month). On this tariff, customers are charged nearer to �3 per cubic metre but they still stand to gain because the standing charges are waived:
http://www.anglianwater.co.uk/index.php?sectio nid=35&parentid=14&contentid=62&pager=1#ptop
If your supplier offers a 'SoLow' rate, or similar, it would be worth monitoring your water usage and doing the sums to see which tariff is the best one for you.
Chris