From my experience, there are conferences where sponsors have a lot of influence on the content. But these conferences are mostly commercial-oriented: talks pre

From my experience, there are conferences where sponsors have a lot of influence on the content. But these conferences are mostly commercial-oriented: talks presenting products rather than talks about the state of the art in the domain. For the venue, it is possible to get it almost for free. Partnering with a (private) engineering school did work several times for me. It's free advertising for them and they are already equipped for such events. Another way is a partnership with an artist collective, provided that their situation with the municipality is well defined.