Tax attorneys must be tax experts, so they should be familiar with tax laws and IRS regulations. They should also understand why you might have overpaid and what you should do to avoid a late-payment penalty.

If you have a tax attorney who is not tax-savvy or who is too aggressive in negotiating with the IRS, this could put you at a disadvantage.
How to Determine If a Tax Attorney is Right for You
Tax attorneys will generally charge based on the number of hours they are working on your case.
To figure out how many hours your attorney would need to complete your case, estimate how much you have paid, the number of hours you think a tax attorney would charge, and the number of hours the IRS would ask for.

Few FAQ’s answered in your case:

Can a tax attorney negotiate with IRS for a payment plan?

Yes, it is possible that a tax lawyer can negotiate a payment plan with the IRS if you pay an attorney and his bill within 30 days of the balance reaching $1,000.

Can a tax attorney negotiate with IRS for an installment plan?

Yes, it is possible that a tax lawyer can negotiate an installment plan with the IRS if you pay an attorney and his bill within 30 days of the balance reaching $1,000.

Is an IRS “tenant” agreement valid for tax debt?

No, an IRS tenant agreement is generally not valid. A tenant agreement is only valid if you are already a tenant of the IRS, but not if you are a tax collector who is seizing your property.