Let's assume your 'some time' costs $5,000 a month. That would make that one year cost around $100,000.

Interest on that sum would be say $5000 a year. So, your 'reliable input stream, say $5000/m' would recover that $100,000 in two years.

From that, I conclude that you do not really need that $3000 a month to do this. The 'only' thing you need is this bright idea.

If I had that idea, I wouldn't tell you about it; I would try and implement it myself.