Exceptions of course are taxpayers who haven't filed many years OR a business that owes 941 taxes. Those cases might be assigned to the field regardless of the dollar amount.
We had written previously when the threshold was announced at $100,000 back in March 2012:
For 30 years, WATAX has been solving every kind of tax problem. Call us at 1-888-282-4697 or email us a description of your tax issue and we'll contact you.