well from a business side it actually makes a lot of sense:

1. the supply of the product is endless, you literally have your pick from billions of people
2. there is no monopoly to go up against, you can be a 1 man operation competing on the same level as the Mcdonalds of humans, inc
3. acquisition costs are tiny, once you have your van and a shack in the woods, your cost become almost zero
4. profit margins are huge. You get ROI of 1000x
5. Scaling up the business is fairly easy.
6. customer satisfaction is not something to worry about, noone will go to the cops, noone will write you a bad yelp review
7. customer retention is huge, since switching costs are too much(too much risk to try a different merchant)
8. You CAN get high on your own supply
9. You have lots of opportunities to upsell. Sure I can sell you that blonde for with B cups for X. But for 2X, we can upgrade her to C cups(not like the person will be able to take her to a regular surgeon).
10. Risks are fairly minimal too. You get a smaller sense than you would for robbing a bank, and they make like 20x money off a single sale.

so I'd say the rationalization is def there, which is why they caught 2000+ of these guys in 2016 in united state alone.