I use dried beans unless I am in a real hurry, always for soups. I'm more likely to open a can of black beans to go with tacos or for a throw together casserole.
I was just checking the prices and canned beans usually cost around $.75 (more or less) for 15 oz (so we will call that two cups)
One cup of dried beans makes around 3 cups of cooked beans (some say 3 1/2), so for a similar package, you would get 6 cups. Looks like the cost of that is around $1.25 or double for the 15 oz package. But you can get bigger packages that are a better deal. And if you buy them in a bulk foods section, they can be much cheaper.
As for the power they take, it is about the same as making pasta. You bring a pot of water to a boil, cover and turn off the heat. Soak overnight. Rinse and they are good to go, but they will still need to be cooked to be completely soft.
I have read a tip on ThriftyFun that you can then freeze portions, and they are very similar to using canned beans. I should try this, seems like the best of both worlds.