I'm not sure about the maths here. For the magikarp catching method, catching a certain amount of perfect IVs follows the binomial distribution, I'm not even sure where these values come from. P(x=1) is 0.164281, P(x=2) is 0.0136901, P(x>=2) is 0.0143139. I would expect the use of P(x=1) and P(x>=2) if you only consider the two cases, but the numbers don't match up, in both cases they are lower, even if you take the lower probability of x=2.
I made a spreadsheet with the probabilities, and I get an income rate of about 160, see attached png.
sources: https://en.wikipedia.org/wiki/Binomial_distribution,
https://www.wolframalpha.com/input/?i=P(x%3D1)+where+x+~+binomial+distribution+p%3D1%2F31%2C+n%3D6,
