<<what's your advice for people who don't have much of a bankroll to work with?>>
You could read 'The Bootstrappers Bible'.
Here's a quote from it:
I am a bootstrapper. I have initiative and insight and guts, but not much money. I will succeed because my efforts and my focus will defeat bigger and better-funded competitors. I am fearless. I keep my focus on growing the business—not on politics, career advancement, or other wasteful distractions.
contact me if you'd like a copy of it in pdf (I have permission from the author to give it to people).