Home insurance cost for Manhattan townhouse?

I'm considering buying a townhouse in Manhattan, but wanted to get a sense of what the insurance cost would be for significant liability and property protection (enough to rebuild the place in cast of, say, a fire), for a townhouse originally built over 100 years ago. I would be willing to take a significant deductible if it keeps the cost manageable. The insurance would be for "tail event" protection (e.g. something catastrophic, such as a fire). What kind of annual cost can I expect? 1% of the price of the townhouse? 0.5%? And what insurance company would I be best off speaking to? I have had a hard time getting a quote from a company who would cover this.