Estate agents over value properties as a matter of course. The reasons are complicated and varied, but one reason is that they will attempt to control the market in certain areas by increasing the price by around 5-7%. Its a no lose bet for them as they just play the waiting game. If it sells, great, if it doesn't they blame the time of year, saturated market etc etc, then reduce the price to what it should have been in the first place.
To be fair to them (as much as I can as tbh I can't stand the industry) often the vendors will overvalue their property on the basis tgat it has a granite work surface in the kitchen, an electric garage door (whatever) which anyone who knows the first thing about property will tell you makes zero difference to a property's value. You can tart your house up all you like, unless it's things like central heating or double glazing it won't improve your property's value one bit, no matter how much that may upset you.
So estate agents always overvalue property, either to try and control the market, or to appease a delusional vendor.
If you go into an arrangement with an agent understanding this principal, it will make the sale of a house you "just want sold" much quicker.
The wording to use is "realistic sake price to get it off the market ASAP". Keep pushing the point to the aren't and they are far more likely to realistically value your property, resulting in more viewings, sooner. Often when properties are "realistically" valued they are purchased by property investors (of which I am one).
These agents are always playing a game. As soon as you know the rules you can control it yourself from the get go. Always remember it's your home, and you can value it at whatever price you see fit to get buyers through the door and get it shifted.
Also, remember how to tell when estate agents are lying.... Their lips move.
Just my 2p, take it or leave it. :)