Just got my bill for a follow-up appointment. Sinc...

Just got my bill for a follow-up appointment. Since they won't take my insurance, I pay out of pocket to see a specialist here. The office visit price more than doubled since the last visit. I was NEVER informed of this, either when making the appointment or on check-in, when I tried to pay the bill in person. If they are this dishonest and unethical with their biliing, what else are they dishonest and unethical about?