Well I am not trying to get your hopes up to much as you could very well have a wiring problem but it sounds similar to what my catera did right before the brake light switch went out.
This thread will show you how to change it. It will be cheaper to spend the intial $20 or so dollars and find out for yourself.
Brake light switch replacement
I actually just reread what you wrote. I can not actually say that I remove both bulbs and found that the middle one worked. You could still try the brake switch. Unplug the wiring that goes to it, plug in the new one, turn the ignition into the run position. If the brake switch was bad the brake lights should be lit up with the new switch at this point. If it was not then the lights will still not be lit up but you can at least take the part back, lie and say it was something else.