Ms.Feldman, I understand your frustration but am suspect at your motives of publishing her name in this forum. As a first step, I for one, would have called JoAnn and asked her why the discrepancy in the price? If this was an obvious mistake on her part then you've assisted another Realtor in rectifying an issue which might have escaped her notice.
I then would have called the local MLS to let them know the discrepancy if I received no response from JoAnn. Now if you've done all of the above and still no change then I'd go the Board of Realtors. And if you've done ALL of the above I STILL WOULD NOT use this forum in the explicit manner naming the offending party. A more generic rephrasing of your question is in order. Please consider our Trulia community guidelines when composing messages as this cast dispersion on the entire Realtor/Licensee community.