I am not a Realtor so take my opinion for what its worth. Selling in an uptrend you can set the price higher and wait for the market to catch up to it. In a downtrend you have to aggressively price your house lower to ensure that it gets some action. Let me give you an example. 4 to 5 years ago a house sold for $299,000 and had you set your price at $290,000 you may have sold yours. A year later $275,000 may have got it done and now houses at $230,000 has not sold. The housing market will turn around eventually but nobodycan tell you with an certainty exactly when that will happen. My opinion is that it will take 5 to 7 years for everything to settle and we have most of the distresses properties eliminated from the market. Obviously if you can wait out the downtrend you will be in better shape but it appears as though it is an expensive investment.
First I would see if the kids want to contribute to keeping it going. Thats a win win for everybody. If not price it low and be preapred to drop it 5% per month until somebody bites. It may hurt now but it's better than paying whilst trying to chase the market down for a couple of years.
FYI, I don't look at your house from the perspective of a Realtor, but as an asset than needs to be sold. If you decided that it is non performing, cut it loose and it will save you money in the long run.
As Terry stated, you'll know when you hit the "magic" price - when you start getting more showings. What was the feedback from the 4 showings you did have? Was the feedback only negative on price or were there other things the potential buyers said? Sit down with your Realtor and have an open, honest discussion. Then you'll need to decide whether you want to continue paying $16,000 per year until you can get the price you want. It might even be better to take a loss of a few thousand dollars now than to continue paying the payments, dues, taxes and utilities.
I wish I had better news. Good luck with your sale.
Long and Foster Real Estate