Shop around get all the agents in your area to valuye your house ,ask all the right questions. eg .advitising,where and when ,no of clients there have on there books looking for your type of property ,how many are in chains who are first time buyers ,cash buyers etc .
Once you have decided on which agent to go with negotiate there % ,the market is reasonably boint so I wouldn't pay any more than 1.5% sole agent.you can do a 1.5% asking price or more achieved 1% if less ,that would tell if there are selling you a yarn and inflating the price to get you on there books than a month later tell you to reduce the price if you want to sell.
First thing I would do is a search on right move and see how many of your type of property are for sale in your area ,if the search comes back with very few it should put you in a strong position ,not unless your house is next to travelers park or the local dump if you know what I mean..
Just remember one thing don't trust a estate agent there are not your friend there are in the business of making money .I am not suggesting there are bad people its just business .