D.I.Y. vanilla extract - we've considered it, but only briefly. Vanilla extract needs a lot of beans and alcohol, and the cost factor just hasn't seemed worth any increased flavor.
But Melissa at The Traveler's Lunchbox has a brilliant habit that turned us around: she keeps a bottle of alcohol in the cupboard, and she puts all her used vanilla beans in it after using them for cooking or baking. The reused beans steep in the liquor and create rich extract. See her post for specific directions.
She buys her vanilla beans in bulk - as do we. Stay tuned for some good sources.