"...There are lots of software-as-a-service companies that take care of calculating sales taxes..." as someone who has worked in this before... The data is not

"...There are lots of software-as-a-service companies that take care of calculating sales taxes..." as someone who has worked in this before... The data is not as accurate as you might expect it to be, tax jurisdictions overlap zip codes inconsistently, the services are expensive and there are the integration costs that are perpetual. all of these challenges can be satisfied, but to dismiss it and go off and assume it's a marginal cost is a tad ignorant; especially for a startup that is being bootstrapped by the founder(s).