Sponsoring an event can be either paying to come and pitch to the group (rather than organising an event yourself), or requesting the presence of some of the Group at an event you are organising.
To pitch to the Group it costs £80 p/hour, available in 15 minute slots.
Requesting the Group have a presence at an event can take a variety of forms from providing technical support or fronting a stall by a 3rd party sponsor at an event you're not available to attend yourself.