There is another Coldwell Banker in town that does not charge the ridiculous fees.
The agency contract is required by the state of MO but for some reason there are different interpretations. I am a Buyer Specialist at the other Coldwell Banker in town. We work as "designated agent". Here is an excerpt from the MO Real Estate Commission Statutes and Rules.
"Before or while engaging in any acts enumerated in section 339.010, except ministerial acts defined in section 339.710, a designated broker acting as a single agent for a buyer or tenant shall enter into a written agency agreement with the buyer or tenant. The agreement shall include a licensee's duties and responsibilities specified in section 339.740 and the terms of compensation."
Legally, if a licensed agent is working on your behalf in MO then Buyer's Agency is required. Some don't abide by it. I have heard (complete hearsay here) that during audits the MREC looks for dates of Buyer's Agency being signed compared to dates of other activity i.e. showings, offers, etc.
Hope this helps. Good luck in your St Charles search.