Vanilla beans are craaaazy expensive if you buy one or two at the grocery store or at a specialty baking store. Like, $9 for two. Unbelievable! That's a ridiculous cost for two vanilla beans and you should not pay that much.
Vanilla beans bought in bulk (usually online) are a way better deal. I've used two different companies, Vanilla Food Company and Beanilla, for my vanilla beans, both of which sell bulk vanilla beans in various types and grades. Instead of paying $9 for two individual beans, I buy 50 beans (1/2 pound) for about $38 to $40. That's 80 cents per bean. Mind you, I'm buying extraction grade beans (grade B) rather than the grade A beans. Extraction grade beans are less plump and less pretty but are just as good as grade A, but they're sold at a lower price.
I started my vanilla extract about two years ago using the method I've described below. I've kept it going by adding more vodka and vanilla beans as I've used it up and it's evolved into this deep, dark, fragrant liquid.
Now that it's about as saturated as it can get, I've changed my method. When I get new vanilla beans, I simply cut them in half widthwise and pop them in my extract. When I want to add vanilla seeds (but not necessarily extract) to a recipe, I take out one of the halves and simply squeeze out the seeds and the bean goes back into the extract. By using the beans this way, I still get just as many seeds out of a grade B bean as a grade A bean without compromising flavour. Plus, I can use that de-seeded bean to infuse liquids or flavour sauces. I absolutely love vanilla beans and I make sure to get as much use out of them as possible.
Homemade Vanilla Extract
500 mL vodka (or rum, brandy, or bourbon if you prefer)
Split the vanilla beans in half lengthwise and scrape the seeds out. Divide the seeds and beans among individual jars or put them all in one large jar.
Another way you might wish to try is to either cut just the tip of the vanilla bean off or slice the vanilla bean in half widthwise, leaving the seeds in the bean, and adding it to the vodka. This way, when you need to add a vanilla bean to a recipe, simply take out the bean and squeeze it down the length of the bean to squish out the seeds. You can still do this with the split and de-seeded beans but you will only get a small amount of seeds.
Pour the vodka (or other alcohol) in the jars and seal tightly. Make sure the vanilla beans are completely submerged in the alcohol.
Store in a cool, dark place for at least 8 weeks. Shake the jars every few days.
After 8 weeks, the extract can be used, but it is best when aged for several months. Keep topping up the vodka and adding vanilla beans as necessary.