Working for a large privately owned fire detection company, we too have every accreditation going, including LPS1014 for fire detection and alarm systems, all quality accreditations CHAS etc etc, the list is endless.
Based on this, generally the figure we would be offering would be under the £1,300.00 figure to supply, fit and commission, using our own labour, therefore the figure of £1,300.00 if those guys are subcontracting part of the works would be realistic.
I cannot believe such a figure of £8,000 has been submitted. If you think, to programme the panel would take an hour or so (including a tea break) and to fit and test the devices you'll be looking at an easy day for an engineer, tops.
What system is currently installed in the premises?