Brian Goldstein writes in the comments:
1. Do you have any estimates available about the processing cost of a revenue neutral sales tax regime? i.e. Would the IRS spend only 40 cents? or 30? or 50? I know you’ve guessed that the smaller N-size of businesses means that they would realize some savings, I’m just curious to know how much.
2. Do you really think that revenue collection inefficiency is a dead-weight loss of such priority it’s worth busting up a nearly 100 year-old established system? I imagine the transaction costs alone would in the medium term be daunting, and rather than shrink the market for tax professionals, just shift the market from individuals to corporations. Corporations don’t just pay on what they sell, they pay on what they own – or not pay on what they could justify not owning. We’d still need an elaborate system of record keeping, checking, statutory provisions, and enforcement to account for those revenues.