Hidden occupation's 3rd requirement

Shane knew that one Diamond coin was roughly worth one million gold coins.

So he could roughly estimate how expensive the mana heart awakening of Igra was.

Compared to his world's mana heart awakening, Igra's was more expensive.

The reason for this was solely because Shane would have to earn this money by himself without anyone's help while staying at a particular stage.

That is if he didn't want to pay more while reaching a higher realm which would increase the price he had to pay.

Considering that mankind had a population of tens of billions, Shane thought that the price of several dozen million Diamond coins might be somewhat reasonable.

Provided everyone were to actively contribute to awakening Igra's mana heart which was not the case.