Symphony makes $2500/month ( http://www.symphonytools.com ). Launched 4 months ago. Back in December, my co-founder and I spent 3 weeks brainstorming and wrote 25 business plans for 25 ideas. And then chose this one. Started building it in January. It's written in Python. Hosting costs about $700/month on Google App Engine. It doesn't cover our costs yet, but it's growing. Hardest challenge so far has been to find wa…
Why are you still on GAE if it costs that much? I learned Django and migrated my projects off GAE a year ago. It was rather painless to learn the bits of Django needed to replace GAE, and looking back it was a great move.
App Engine has it's disadvantages as well. At one point I used typhoonae (open source framework that let's you run you GAE apps on EC2) and was about to switch, and then decided against it.