I have to agree with M1chae1.
300k is a sum, that would, from the standpoint of an investor, rely on previous work, showing that you can indeed work with a budget. I believe, that the mentality would suffice as to that of your audiences, too. You have to believe that the majority of your audience would be lovers of film/film-makers, there's never been so many "film buffs" turned film-makers. The digital era has diminished a barrier, that you seem to be somewhat neglecting.
Through ticket sales, and the distribution of, let's say, you'll travel a lot, sell tickets where you can, Independent DVD stores, Small cinemas, publicity from your local radio stations/newspapers, social networking via film forums and sites along the obvious.
The above just a sample of combined methods, of the sum you are trying to accomplish. Can you possibly suggest, without the "buzz" of a festival circuit, generated by a solid short, or 5-10k feature, that "labor" is the "key"? In this age, I can offer an opinion for what it's worth, that it simply is not.
A first feature, to be at such a budget, initially, is something I'd personally look upon as potentially damaging to the experience, you're entering the prelim Olympic double-breast stroke before you've indeed learned to swim in the feature pool.
EDIT.
*The above, is as i know that you state to have "connections" not dismissive of your capabilities on a feature set, merely the "togetherness" needed of a group, to accomplish, first time, a feature of the stature to gain a "Cult following". Perhaps it's me, but I wouldn't dare jump into a feature, without working with the crew for a long time, i have to trust everybody i work with. Working on 5-10k budgets, shorts, anything as long as you guys are together, that you progress, is ideal for what you're displaying, as a unity funding.
I'm again, not ravishing the essence of negativity, a pessimist is a title I'm yet to own. Be it that I'm conscious of time, I cannot see, in the current climate, a first-time feature gathering a budget near your target.