With all this talk about Interest, youve sort of buried the lead, which is a 1000% increase in steem price over 5 years (which is on top of the recent 2000 percent increase).

In your million dollar scenario, 900,000 of that comes from the market increase, not the interest. Regardless, youre overestimating by quite a bit, even assuming the 10x increase.

A) because steem power interest behaves as though its compounded annually, not monthly.

and

B) because not all your blogging steem power will increase 10X, since youll get some later on. So for exmaple the 15SP blogging reward you get in the last month of the 5 years might hardly increase at all.

https://steemit.com/interest/@sigmajin/how-anonymint-and-bacchist-both-got-it-wrong