Great question. Your local sheriff (or a third-party vendor) may be hemming and hawing about the rate. Here’s the reality: the law is extremely ambiguous and there’s no clear answer. Papers around the state charge different rates for tax sales.
That said, LPA’s position is that La. R.S. 43:205 allows for the charging of 90% of your open commercial rate on tax sales. 43:205 (and other statutes) provide for a $5, $6 or agate line rate in the more populous parishes. However, all of those statutes deal with “state agencies,” it is LPA’s position that the sheriff is not a state agency and is instead an instrument of local government like a Parish or School Board. Because the cost of advertisement is ultimately borne by the tax sale purchaser, the 90% rate appears appropriate. However, given the controversy surrounding this issue, you may need to consider whether charging less, or even the $5/$6 rate allowed in more rural areas, will keep your relationships with the local sheriff on better terms.
Again, what rate applies really depends on where you are and what you are publishing. The balance of public notice is extremely important, as threats to public notice are real and always start with a local government complaining that they are being overcharged or unnecessarily charged. Tread responsibly!