You will get that down to 8 hrs max, so 200 quid for a normaldays work is pretty good going in my book.
Always remember 3% of something is better than 10% of nothing.
It seems to me that people on here go for the big prices, whether they do really I am not sure, but if you can earn 200 pounds a day that is good money.
If you get to quote for a neighbour, remember they will have discussed prices, so be carefull.
You may end up with a full weeks work out of 5 customers, so be careful and don't get too greedy.