I actually don't see how this is a major 'programming' problem for a website. I'm charged sales tax on stuff I buy from BRS because I live in MN. I assume that based on my zip code whatever software used on the webpage has a database of tax rates in MN and its automatically calculated (many locations have different sales tax rates in MN). I can't see how adding a tax rate database for the rest of the country would be that difficult. I do see how it would be onerous to prepare sales tax reports for 50 states for a small business... I wonder if state auditors from one state have the jurisdiction to audit a company in another state.
Yes the auditors do have the jurisdiction to audit a company in another state. We have auditors from states like New York and Illinois fly down to our office in Texas and they will be here anywhere from a day to a couple of weeks.