Phew!
Why on earth work so cheap?
I was charging those prices for a semi 10/15 years ago.
You are WFP so quicker than before, but your running costs are now far higher than before, dropping your prices so low will eventually eat into your margins.
Did I read that you used "WE" when referring to the work you have?
If there are two of you then £750 per week isn't so good, plus maintaining that workrate day in day out, for month after month isn't really sustainable.
To advertise a semi at £6.50 just has to be misleading, some will have more windows than others, some will have conservatories and porches, some will have access issues...
If the average price in your area is around £16.00 for a semi then that is pretty high, as others have said, don't put in such a huge drop in price...why on earth would you want to work so cheap?
I know you might work out that you can knock out 5 an hour ( I am assuming that you are in fact a one man outfit) over the course of a day, and maybe even average that over a working week, but 5 an hour is above the average, few will manage that, especially all day long and then all week long.
Even though 5 in an hour isn't exceptional very few will have work that is so compact that they can sustain that day afer day.
A more realistic average is 3 an hour over the course of the average person's round...and even that is allowing that almost all of your work is is 3 bed semi's!
that way, if you want to earn £30 an hour your average price will need to be a tenner.
At that price you are still far cheaper than your opposition, and when you have days where you knock out 5 or 6 an hour you earn very good money indeed.
Being fast doesn't mean you have to keep dropping your prices!
This is how you boost your earnings, you are quicker than the opposition (not that it matters if you aren't of course) you are cheaper than them but are still earning a top income (theoretically) but even on poor days your income is still ok.
And of course you also need to factor in rain affected days, holidays, bank holidays, lazy days, days lost through illness and those days where you just can't get it together, days when your equipment will breakdown.
If you are happy with your earnings then more power to your elbow...but you are not working to your potential, I'd say you are shooting yourself in the foot.
Ian