The cost of a lottery ticket :-)
If I had to break it down:
After that, I leveraged my current network of business associates, offered "workshops" around my city and signed up enough people locally to make it self-sustaining and profitable enough to pay myself each month.
Because I already had another business this was a service of, the LLC was taken care of, I was already paying an accountant, I already had the computers, software, etc, to make it all happen, taxes were being paid... But if you have to buy all that stuff, you're probably looking at a couple thousand more.
I think the costs of startup can be devided into 2 broad groups.
1) amount of money to bring the idea into reality.
2) amount of your time to bring the idea into reality.
with internet startups the 1) can be within $100.00 if you do all the programming, marketing and run a 1 man show. This in turn requires a lot of your time which makes 2) really high.