I'm curious where your 2% margin came from in this estimate. From what I can tell, that number is often quoted as Amazon's profit margins, but I'm not sure smaller more-specialized online retailers necessarily need to match Amazon's low margins.
If you are manufacturing something then the profit margins can be much higher. However, for retail 2% is fairly solid and likely above average when you include people losing money, but not outstanding.
Enough to live comfortably on, but not exactly a big money. Further, the ruling applies to all taxes and has no cutoff under 100k/year required.