The real estate market is more complicated than it would appear from reading the papers. There are things that are selling, and selling quickly. There are other properties that are hanging around, some without even being shown. This has been true for a while now, but it's not what people expect in a so-called "buyer's market" (read "bad real estate market").
In more traditional renditions of a buyer's market, there are not enough buyers, and so they can bid low on properties, and sellers will have to take low offers if they want to sell. It tends to be true across all segments of the market, from starter homes to mansions. In a seller's market, the opposite occurs: People who want to get a property need to move quickly and bid high, or they will lose to other, more motivated buyers.
This market has aspects of both. Many people have listed their properties a long time ago, and those places have been sitting around. They are often overlooked by agents and buyers, as they can be considered as tired, and usually as overpriced. Other places come on, attract attention right away, and sell quickly, sometimes with multiple offers. What's the difference? Sometimes it's location, or staging, or size. Sometimes there's just a buyer who needs what a seller is selling, and needs it right away. More often, however, it's perceived value. The market--that amorphous body of economic value judgment--rates the property as a good value, and that sparks interest.
All of this makes it difficult to price properties. However, the possibility of multiple bids and early interest means that it's hard to underprice in today's market, as buyers will bid the price up to where it can/should be. It's easy, unfortunately, to overprice. Many sellers look at what's on the market at the time, and place their home in the range that they feel it belongs, without distinguishing between the overpriced inventory and the value properties that are getting all the interest. And that's a big mistake. Look at what's sold, and do it with a clear eye. Then listen to your real estate agent, and get your property into the sold column. Then you can become a buyer, and use all that knowledge to get a great value!