I used to run a third space.
They aren't free. they cost money to run. Rent has to be paid, utilities have to be paid, etc. our expenses per month were typically 600-1200 dollars. that's dirt cheap though, because we had a sweetheart deal on the rent. typical rent for the space we used, commerical rate, was about 6000/mo, and adding in utilities and taxes and such would have brought it closer to 8000/mo.
We operated on donations, so people still typically had to pay 10-20 dollars to use our space. It wasn't mandatory though, but at least half of people who showed up often paid, a few people paid more than we asked. many months we went net negative, and if we had several months of losses we'd have had to shut down. usually on the year we were up maybe $1-2K.
Everything has costs. Someone has to pay those costs. Nothing is free.