Is 60 days too long for a price increase notice?

I've been delaying a price hike for months out of fear of mass churn. We finally decided to bump our rates by 30% and gave current users a two month grace period before the change kicks in. We sent a simple direct email explaining that our server costs went up and surprisingly not a single person canceled.

But now I'm wondering if giving people a two month window just leaves the door open for them to shop around for alternatives.

When you bumped your pricing how long of a buffer did you give existing clients?