Barbara Houston is a CPA with her own accounting and tax practice. One day an audit client asks her to represent him in a conference with the IRS about his prior years’ tax return. It seems the IRS is claiming that the audit client owes $50,000 additional taxes. The client agrees to pay Barbara 20 percent of the amount of additional taxes saved after the conference with the IRS. What are the ethical issues of concern for Barbara under the AICPA Code and Treasury Circular 230?