The number I've heard is approximately $2500 per capita.
Most folks proposing flat sales taxes tend to propose taxes in the 10-15% range. So, someone spending $17k-25k per year would equal the property tax in NH.
Since property taxes are actually paid as a lump sum, they are easier to get folks worked-up about, in trying to keep them down. Sales taxes are a few cents or a few dollars at a time, many times over, so they sneak under the public consciousness, and small changes in the tax rate are not met with as much opposition.
Last ballot I saw, on the other hand, actually listed what impact each spending item would have on the tax rate. Eg, "if this item passes, you will have to pay $2 more per thousand next year." Makes it much easier to keep spending relatively in-check.
We had a warrant article, here in Grafton, to have the tax bills delivered a week before the town election. That would have been fun...
Joe