First and foremost, limit your liability as far as product and service issues with a CONTRACT. That is an industry standard practice.
On to General Liability (injury and/or damage):
Most major insurance companies offer liability policies for a business. A policy won't run more than a few hundred bucks a year. There are many very compelling reasons to have liability insurance when operating a business. In my opinion, I would consider the advice not to carry a policy if you are in business to be somewhat marginal. For starters, there is no way you can predict what can happen. I have witnessed countless mishaps over my 35 years in business, large and small, including things that wound up in court or as an insurance claim, and in todays litigious society a business owner is a prime target for litigation over the flimsiest of circumstance. You can end up paying cold hard currency for a very long or time if things don't go your way, house or not. If someone comes after you, the only thing that you can count on for sure is a huge mess, so leave the predictions of other things to the armchair Perry Masons, and cover your butt.
If you have insurance, the company lawyers will go to bat on your behalf if they feel they can save money over paying a claim, and if they don't, they will simply pay the claim (which is what usually happens and normally your only inconvenience is a short telephone interview). From front seat experience I can tell you when you wind up in court, even if you win, you still lose. All a win does is bring relief from a year or maybe even years of time wasting hair pulling BS. Time you will never get back.
Also, many times a judge will not award monies past what a reasonable policy will pay, unless there has been malice or gross negligence. However there are some judges who consider lack of liability insurance to be negligent, and mete out punitive judgements accordingly. This is a general observation, again, nothing is for sure in litigation.
Also, many venues want to see proof of insurance before you can shoot there. In my opinion, if you are really a professional and really in business, working for people who pay you to be there, it is part and parcel of an honest business practice, and most clients assume you are an above board business person and so are insured.
In regards to the OP, general liability is purchased in million dollar increments. I have had liability through American Family, price was in the $200-$300 range for general liability of 1mil. Currently I carry 2mil (standard for commercial work in parks) through State Farm, annual policy is about $425. Peanuts if you are for real. Just open the phone book (yikes! There's a dated statement!) and start calling around and you'll get the gist of it quickly. Agents expect to be questioned and shopped, that's what they are there for, so don't be shy.
YMMV but thats my 2 cents FWIW.