It's a lot easier to reduce the price than to raise it!
Not always. Reducing the price on a subscription-based product like this can make the early adopters feel like suckers-- whereas it's easy to grandfather them in on a raise in prices.
How do you feel about retroactively applying the new, lower cost to early adopters? I'm on the verge of doing some extensive A/B price testing and plan to do this with any users who buy at a higher price.
I'm not sure how I feel about that, actually. I'll be interested in hearing what your experience is with it.