My daughter said she had a small leak and it was sealed and the unit refilled with fresh Freon. Then the next year the unit didn't perform well and she called the installer (a friendly neighbor who did refrigeation work had refilled it). The installer's tech told her she had air in the line and it would cost $200 to remove the air and refill it. She didn't have the money at the time so she said she would think about it (the unit still was working just not well). This year she could afford it but when she called the installer they said they would have to send someone out again to check on it. That tech said it had air in the lines too but this time he said it would cost $800 to remove the air and refill it. Is there a reasonable cost for this kind of repair? As far as she knows there is no mechanical repair needed just the refill.