Cheap landlord insurance
The key to cheap landlord insurance is fairly simple: keep your premises in good condition.
There's no direct link between cheap landlord insurance and the condition of your property, mind you; but companies may not feel obligated to pay out to a property that was in poor condition in the first place. They'll inspect the property and determine whether or not paying out to the landlord will actually better the property in the long run, rather than restoring it to the status quo (which is what insurance companies are supposed to do).
Keep in mind, too, that a catastrophe isn't likely to hide examples of your inability to properly maintain the premises. Let's say there was a fire that consumed almost the entire building. You may think that any evidence was burned up, and you can subsequently and confidently collect insurance money: however, inspectors are trained to look for examples of neglect, and will thoroughly pick through the rubble. More, underwriters for the company will doubtless investigate your records and find out if you have been assiduous in your maintenance.
Cheap landlord insurance may not be the right brand for you. To go cheap means to risk not having a number of things covered; as always as a landlord it's important for you to shop around, but the variety presented may not be enough to sufficiently cover your investment. You also need to ensure that you've got the right kind of policy: if you rent rooms in your house, for example, standard house insurance will be insufficient to cover the balance. And getting the proper landlord coverage won't be as cheap as the standard brand of insurance.
The best way to get some cheap landlord insurance – or at least as cheap as you're likely to get when dealing with a tenanted building – is to join a landlords' association. These groups are dedicated to catering to buy-for-let investors, and will often let members in on policy rates with associated companies that are substantially cheaper than a landlord being thrown to the market on his own.