If you are experienced and own some of the gear already, you will know the techniques to make a professional-looking movie for as little as $30,000 or so, but realistically one would expect to spend six figures at the very least. Half a million dollars could get you a professional crew for a few weeks if you could do some of the post production and pre production yourself.

A feature film is an enormous undertaking, for some people it is the most stressful, expensive and important thing they will have to be responsible for on a professional level. You aren't going to get a sense of it from asking questions on message boards. And you probably won't make much if any profit from it, if you don't end up losing most of the investment. Most indie films are total financial loses, even from established filmmakers many films don't get distribution outside the festival circuit, therefore they don't make back the budget.