Agree. My experience in pricing was that we were locked in to the initial price we set. (And the CEO did it by accident. Oops.) No one could stomach raising it.
Then again, we didn't actually try raising it and face backlash. It's possible we were just too cowardly to try and fail.
I tried something similar... Our CEO set the price of our email service too low (oops). But unlike you we faced the music and doubled the price only a year after. The backlash was much smaller than I anticipated. We marketed the price hike by adding some requested features and made the payment term half as long so the price seemed to be the same. This made it easier for our customers to swallow. Of course we lost customers, but not enough to make a difference (about 5%).
Then again, we didn't actually try raising it and face backlash. It's possible we were just too cowardly to try and fail.