Even if Mario and Sandra worked diligently on their own ranch, they wouldn't have too much of a surplus for the next year or two, since it would be thrown back into operating and expanding the ranch.
It would take at least five years for them to get to the level of earning 200,000 a year.
Even then, they would never earn as much as what Selina and Gold Nugget did.
Also, Selina and the dog head didn't have to worry about laundering money. Luke took the dirty money and gave Selina dividends instead.
Unlike Luke, who had only been able to stash this dirty money in his inventory at the beginning, Selina had it much better.
But Luke wasn't disappointed.
If he had laundered the money back then, he would have to think of a way now to turn legal funds into dirty money in order to pay his allies in South America and Europe.
Conveniently, he could use most of it with these people