I would be interested. When I was teaching dog classes I had a great space that didn't cost much in north Seattle. But it was owned by the state and they closed it due to budget cuts
Depending on how many wanted to get together we wouldn't need that much space (I'm thinking basketball court size?). There is a building in Kenmore at the north end of Lake Washington (across Bothell Way from Kenmore Lanes) that has a sign on it saying something like space for rent for parties & wedding receptions and I think it said $60 per hour. I will make sure to look closer next time I drive by. If we got it for 5 hours, that's $300 and if we had 10 people selling, that's just $30 each.
I have no idea if that is a good rate or not, but it is an option.
No matter how we do it nobody is going to get rich, but it would be a cool way to gather, swap gear and lies, and put faces with names.