I used to do an awful lot of builders cleans, and as we all know they are darned hard work.
Providing they are not georgian or leaded style windows, if you allow a minimum of 3 times the normal price you should be in the right area.
Rather than saying a particular price that is.
Every area varies in the sort of price you can charge, for some the average semi is £15.00 and above, for others it is more like £5.00.
For me, that house looks like a place I would charge somewhere around £20-£25.00 for.
So that would be somewhere around £50 for an inside and out clean.
Therefore my own price would be 3 times that for an initial clean - £150 or thereabouts.
There is also a skill all of its own to doing initial cleans, I'll warrant that although it took you all day, it would only have taken me around 3 hours tops.
Using the correct 4" razor scraper, such as the Unger stainless steel one for instance and having it clipped into a squeegee handle makes a huge difference to the time it takes to knife off a window, you can also use an extension pole too, easy to pop the squeegee handle onto a pole of course.
That house isn't your standard semi of course, one of those is only going to have around 12 windows, so you should be able to initial clean one in a couple of hours easily, if you are doing a lot of them you will also be very adept at it, the speed you will do them in will be corrospondingly quicker and as a result your price will also be sharper and more competitive.
Time I got to work!
Ian