The only cost I ever had when I belonged to a guild was my annual dues. We never even paid extra for guest speakers or to take a bus to a quilt show!!! We did have an auction once a year and you could donate ANYTHING you wanted to-or nothing at all--and were not forced to buy anything either. We also had a "yard sale" at one meeting a year, where you could clean out old quilt magazines, fabric or patterns that no longer inspired you, etc and donate them for sale.
Other than classes I cannot see why a guild would be asking you for more money.