80k gives and 80% chance of paying back 90k.
So that means you are taking a 20% risk for only 12.5% profit.
If you did this 100 times, 80 times you would make 10 grand, for a total of 800 grand.
20 times you would lose 80 grand, for a total of 1.6 million.
On average, you'd be throwing away 800,000 bells per 100 on that strategy.
If that's how it works I've been wasting a ton of money. /sigh.
At 30 grand per, you'd make 60k, 30 out of 100 times, totalling 1.8 million.
You'd lose 30 grand 70 out of 100 times, totalling 2.1 million.
Total loss, 300k. Not as bad as 80k per, but still a loss.