Chris offered a different perspective or approach to posters that may be a terrific option in this instance. Instead of taking a traditional printing approach to things like we normally do, on low quantity 1 off runs, large format photo processing is a cost effective production option.
As such it looks like we would be able to do 24"x30" posters on photo quality paper for $15.00 or a 30"x40" for $25.00. Several options for everyone to consider.