All very valid points indeed. I appreciate there are other over heads to take into account, especially as the company runs vans and employs admin staff etc.
I spoke to them again, here are the actual specs.
1) 8 hik vision cameras. 2ce56H0T-IT3Z. Trade price seems to be £65 so total cost £500.
2) DVR is HS7208HUHI-K1. Trade price £360 with 6TB HDD.
Total hardware £860, round up to £950 for any bits and pieces.
As I said, all cables already in place, with power, ethernet and telephone line in place.
6 cameras at top of ground floor level (so small ladder) and two cameras higher up by the roof eaves.
I don't want to come across as one of those people who doesn't want others to make a decent living, I'm genuinely not one of those people. But £1000 on top of the hardware costs just seems a bit steep for one days work.