I think you're leaving out enforcement costs. If you're little and scamming a few $k here and there, the ROI (Return on Investigation) for the IRS to go after

I think you're leaving out enforcement costs. If you're little and scamming a few $k here and there, the ROI (Return on Investigation) for the IRS to go after you is tiny. It's probably not worth assigning an investigator. If you're HUGE and scamming billions, the ROI is there but you also have the capabilities to defend yourself, obfuscate things, etc so it's unlikely they can destroy you. Therefore, it's not one investigator but a team with forensic accountants, potentially informants, etc. For everyone else, the danger is in the middle. Where you have enough that you can lose a life-destroying amount but you don't have the means to protect yourself. That is a great target for investigators. In short, as you gain more, be careful and have a good accountant who follows the rules to the best of their ability.. until you can make the rules. Oh crap.