Make sure you have someone in the city where the regional is being held to handle all the logistics. If that is done well, and planned well ahead of time, attendance will be good and people will be happy.
Schools are always good for locations to keep costs down.
Our recent regional was cosponsored by the NLG Foundation, so we were able to get the school at no cost. However, I wouldn't worry too much about some loss of money, as a successful regional will lead to new members and increased dues and maybe even some donations. Get information out early and often about plans as they develop. The more people keep hearing about things, the better the attendance, which is the surest way to avoid losing money. Decide on program content as soon as possible, but be flexible as conditions change.