Most of them have a relatively low limit of liability. 98% of folks would be better off on self insuring. 

This is the whole reason for limited liability.

@Jon Gorham Student housing can be a great investment just make sure that you use really durable materials (high traffic carpets, stain resistant paint etc) to help the house stand up to the potential beating it will take from the tenants and remove things that break easily or increase your liability (IE ceiling fans).

You may have "I walk away with no liability" clauses and disclosures, but when your assignee fails, or the seller screws the end buyer, guess who's back in the middle anyway.

There are a LOT of uninsured contractors who can do work for you on the cheap in Buffalo, but the second one of them falls off a ladder doing your siding, you're boned.Make sure every contractor working for you has both liability and worker's compensation insurance.  

A sole proprietorship with enough liability insurance is all you need to get started and if the property/s are too big .

Under Florida law, the buyer can legally transfer his or her rights in the pending sale to an independent third party.Which means, the deal may go through with a buyer who is different from the one who signed the contract (the assignment provision in most standard contracts also contemplate whether or not the original buyer will be released from any liability under the contract).  

All in all though, the hard base + 20% is pretty standard to cover the costs of running the property, and hopefully keep u above water if large capital expenses hit like a new roof, appliances, etc...I do not run under an LLC, though do use umbrella insurance to cover any large liability risk.  

Real estate is definitely a good way to reduce your tax liability.  

Traditional home owner's insurance isn't always comfortable with the new liabilities that comes with rental properties so their coverage will likely be less and the policy may end up being more.