Anyone use the mini fluorescent lights?

[AllegroRondo]

I'm considering switching from the standard bulbs to compact fluorescents after watching an episode of Mythbusters, of all things. They were testing the myth that you save money by leaving a light on continually because it lasts longer (busted).

The data they collected showed that a compact fluorescent bulb uses about 9 times less electricity than a standard filament bulb. That really made me consider switching. But, pricing them around here they cost about $3-5 each, vs. 50cents (or less) for the standard ones.

Do the fluorescents last considerably longer?
Is the energy savings enough to overcome the initial cost of the bulbs?
Where could I buy bulbs more cheaply? (Costco?)