Have you priced really large chalkboards? They can get expensive. I love this idea I spotted at an antiques show this year.
Just get an old frame (and old frames without pictures are pretty cheap). Spray paint a piece of board with chalkboard paint and attach. Or even better, first with magnetic paint and then chalkboard paint. That way you can use it as a magnetic memo board, too. Easy. And good-looking. (Just like my friends. Yea, I'm talking about you.)