I often find that alarm & extinguisher contractors sting customers with over provision & over pricing - I do an FRA and make recommendations, return the year after to find that the works have been done to a category above what is required, the cost was equivalent to using gold plated MCP's and often an important aspect of the cover has been omitted.
I'm doing more & more project work now with clients to supervise specification and quoting of systems, etc and the cost savings are amazing, even though I don't always recommend lowest quote (usually due to concerns about quality/competency).
I've reduced a £20k L2 quote to a £6k L5 in the past, resulting in the works being done and a wholly inadequate existing system finally (after years of trying) being replaced.
I see too much of £80 for a £13 8w fitting, £180 for a £50 extinguisher, plus lots of over specification (look the room has a sink and a kettle - fire blanket & 2kg Powder extinguisher needed!), plus incorrect specification (6 kilo Powder in an office, foam for a 40 Litre fryer, heat where smoke head required, missed exit lock interfaces).