Here is the best way to appraisal you domains name for free
1- Get the appraisal through 3 of free appraisal domains web such as leapfish , nameboy and estibot .
2- Take the higher appraisal an devided it to 3 for ex. $900 will be $300
3- Take the lowest appraisal an double it $200 will be $400
4- Take the medium appraisal and cut 10% from it for ex. $300 will be $270
5- Finally take the average of the 3 results above which is $300 plus $400 Plus $ 270 : $970 devided to 3 The result $323
GOOD LUCK