What does monitoring cost?
A monthly fee, and the number to ask about since it outlives the install many times over. Check the contract length too, because some are multi-year.
Can they take over my existing alarm?
Often yes, depending on the panel's age and brand. It is usually far cheaper than a new system, so ask before agreeing to replace everything.
Where should cameras go?
Entry points and approaches rather than pointed at the whole yard. A good installer will walk the property and say where coverage is genuinely useful rather than selling you a camera count.
Are there privacy rules?
Yes. Cameras that capture neighbouring property or a public footpath engage the Privacy Act, and an installer who raises it before you ask is one worth using.