I'm against charging people to participate. This is meant to be a bartering system and bartering is defined as "To trade goods or services without the exchange of money."
Paid training programmes already exist here in Jersey and I'm sure Guernsey has them also. Nothing against paid training but that is a skills for money swap, whereas this is purely a skills exchange.
I share your concern about costs involved since people seem to gravitate to the Digital Jersey Hub for this type of thing. As a non-member, it is off-limits to me (for those unfamiliar, DJ are a Limited Company selling £200+ co-working membership plans).
It can also be a very noisy place with a presentation I gave being disrupted by DJ staff speaking very loudly and with a total lack of concern for others working around them. Fortunately there are plenty other options.
We've a large, comfortable library with WiFi throughout, and I have confirmed with the Chief Librarian that we can use the library for meetings. I looked for other alternative places and many exist. Coffee shops, or even a business' conference room, if you can find an employee or two who want to participate.
This is meant to be a community initiative and I'm happy to listen to feedback and consider changes, but those are my thoughts on how to do this for now.