The highest sales tax in California that I can find is 10.750% (lowest 7.50%). The highest in Wyoming is 6% (lowest 5%). That's not a wide spread. On many MANY items the existing profit margin is north of 30%, but even leaving that aside. Adding %10 to your base price to have a single price just means that in lower tax markets you're making more money. There's no obvious situation where you make less unless you intentionally under price your products and it eats into your margin.