I did it 12 months ago
Last year in the last week of December, I spent some time going over my prices and decided it was time for an increase. Most of my services went up $10 to $30 and that boosted each final invoice an extra $20-$40 from that point on.
Why did I do it? I decided that it would filter out some bad customers, and I would make the same money in 10 jobs, than what it used to take 13 or 14 jobs, so I would be able to dedicate more time to my clients that did not have a problem with my rates.
12 months later, I can tell you that:
1. I filtered out 5 people that I was hoping to lose to competition anyways
2. 10 people that walked away due to the new rates came back ( When they left. I was polite about it, and made sure to recommend the geek squad

), so I assume the rates made me look like a good deal even after the raise.
3. Business did not slow, I still have this whole month to go, and I already did more jobs this year with the new rates, than last year with the lower rates, and if you add the extra money on each job, this year has been awesome.
Good luck on your decision.