[idlewords]

If you want to live a programmer's lifestyle in San Francisco, then by all means keep your programming job. For my part, I decided that not having to enter comments into a spreadsheet marked 'Game Changers' was well worth a 75% pay cut.

The 'realities of business' are not expensive for a sole proprietorship, if you are frugal. At $10/k a month, I could live like a king.

[dnsworks]

And if you needed to scale? If you needed more servers, bandwidth, or staff? Then what?

[idlewords]

If you're making $10k/month and feeling pressure to grow, that sounds like a problem worth having.

At that point I don't think it would be hard to find an investor (other than the OP) to help out.

[Retric]

Most company's grow from either:

A) Borrowed money.

B) Rolling those profits back into the company.

Assuming lead time is less than a year and the profits are already significant both of these options can grow extremely fast. However, just because you can pay someone a reasonable wage to do what you do does not mean it's profitable. It's easy to throw a lot of time and money after a bad idea that only seems to be working.