The value of your property depends on several factors: 1) Type of Property
2) Number of Rooms
3) Conditions of Property
4) Location
The best way to gauge the price of your property is to look at a local property newspaper for properties similar to yours and with a similar spec. Remember that the price depends on the location within a town, village or city.
When you have decided on a price, please be realistic. The higher you price your property the harder it will be to sell it.
If you prefer you could get an estate agent to value your property for you. They will probably try to get you to sign with them but why would you when you could save so much money by selling you property yourself?