In article ,
Lurch writes:

I don't think so, a top end panel will eat that £150 in one go.

and you can go significantly higher that that;-)

And contrary to popular belief it takes time to service an alarm, some
people refer to just typing a magic number in the panel, some
rougharse would do this, sit in the car for a bit then get you to sign
the service sheet. If it's done properly the entire system is
physically checked and cables are tested, as is the functionality of
the system. This is all noted down in your service record, which will
be provided by a reputable installer.

Never seen any alarm service include explicit cable checks.
Normally every detector is tested, including a check of
coverage area. Sometimes, repositioning of furniture can
render an area uncovered, and need a detector to be repositioned
or supplemented. Also testing of sounders, central station
signalling where fitted, battery conditions, etc. Some service
contracts include replacement of sensors and/or panel at a
certain age, and all should include periodic battery replacement.
A good service engineer would also spot any upgrading which
might be necessary, e.g. due to a change in the use of some part
of the covered/uncovered premises.

You can then use this to gain a discount on your house insurance,
providing the installer is accredited with some sort approvals from
the SSAIB\NSI.

That's a really bad idea. Look to see what insurance cover you
forfeit if you do this, and the premium reduction isn't worth it.
Even if you do have an eligable alarm system, you are probably
best advised not to take any insurance premium discount on that
basis.

Insurance companies generally won't discount a DIY installed system.

Generally, your house insurance discount is roughly equal to a yearly
service visit so by DIY'ing it you're only saving a bit of money now,
but you get what you pay for. A bit more spent on a system installed
by someone reputable will get you a better system.

--
Andrew Gabriel