That is ignoring the enormous externalized costs. I have known business to have spent hundreds of thousands of dollars in professional services when being investigated that have done absolutely nothing wrong.
I think the person you're replying to means "violated the tax code in a minor and non-malicious way" whereas you mean "literally did not violate the tax code at all".
That's for a reasonably typical (and by no means aggressive tax positioned) MFJ + 2 kids return.
Considering that anyone who actually looked at the tax packet should have figured out immediately that the only fault was a mistranscription in the code, they must have wasted quite a bit of money to gain back ultimately nothing.
Thankfully I had records and an accountant, but a very stressful situation to find yourself in.
A notice is not an audit. If you're being audited, you'll know. The IRS examiner auditing you will make sure you know who he/she is, and they will be your primary contact with the agency for several months.
I owned a business that was randomly selected for an NRP audit a few years back. Spent 35 grand on CPAs and defense. After 4 months of an "up to the elbow" exam of our books, received this from the IRS:
"After our audit, we are making the following changes to your return:
"
...that was it. Nothing. No changes. Not even embarrassment or "lol just doing my job, them's the breaks kid" attitude. A total goat rodeo, the entire process. Imagine having to justify every cent on the books in OR out -- for a $2MM revenue business -- 3 years after the return was filed. Seriously impossible. Worse, just before the above letter, we were offered a settlement offer from the IRS for $20K -- to make them just go away. We declined.
Spending more, ideally, should also mean spending on simplification. Making it easier for both people and businesses to pay their due, and costlier not to. Reducing the externalities, not increasing them.