What are some ways to organize conferences at a very low cost?
My answer to What are some ways to organize conferences at a very low cost? on Quora
Find a venue sponsor: venues are the biggest expense for most events, and if you can find a company with their own conference-suitable facilities who will provide the space for free you’ve just massively slashed the cost of the event. Most BarCamps (at least in London) work on this basis.
Get other sponsors to pay for as much as possible. Getting them to pay for things directly (e.g. they pay for the pizza delivery) can sometimes be simpler than having them give you money which you then spend on things.
Have speakers who are either from nearby or who have their travel expenses covered by their company—developer evangelists from larger companies for example. That way you won’t have to cover their costs.
Rely on volunteers for helping out with things like registration, AV setup, and the cleanup afterwards.