While I can't predict the future, in all of 2008, 2009 and so far in 2010, avg. days on market (DOM) for Mandan single family homes, duplexes, twin homes, etc. was about 90 days. In March 2009 DOM was 112, April 2009 DOM was 96.
When I looked at only single family homes priced from $150,000 to $175,000 in Mandan, in April 2009 the fastest sale was 34 days and the longest sale date was 103 days. I would have to do a market analysis to give you a more accurate number. The condition of your home, location, number of bedrooms, age, etc. and of course the price of your home will all have a big affect on the number of days your home will be on the market.
If you want a market analysis, there is no cost or obligation, just Information. Call me at 701-220-3348 or email me at: MarySplichal@Realtor.com.