Slightly off topic....
Regarding putting prices up by unsubstantiated amounts, one of my clients had a clause in their service agreement that gave them the right to audit my books to ensure that the rate I was charging them was reasonable. That one lasted about 2 seconds once my lawyer saw it. I doubt they would allow me to examine their books and capability to pay whatever I want to charge them! It took me over 6 months of legal wrangling to get that (and other ridiculous clauses) sorted out, and every time they would try something else on, my hourly rate increased.
Ironically, they are one of my best clients now.
I have put my rates up 10% this year. My expenses increased by more than that. PI insurance was particularly memorable with a 30% hike. Cunts!