- Outsource non-critical tasks using upwork or odesk for under $1k

- Raise some from http://www.indie.vc/ and then, upto 30% of your ARR as debt. Repayment done as x% of your rev.

If you think, these two steps will charge you up to build & grow this business to 10m or 100m revenue biz, then don't sell.

Else, $12m is pretty much FU money. Buy 250 bitcoins, buy bunch of rental properties, invest in your health & fitness. And, travel a bit to come up with the next idea.

I have sold two companies in last 5 years. But this time, I'm building bootstrapped business with an aim to remain bootstrapped till we touch $100m ARR i.e. building for long term

All the best. There is no right answer to this so, in future, never regret whatever route you pick at this juncture.