The value of domain name is not stable, it have more to do with the interest of the buyer. Two domain name appraisal tool websites displays different value for www.bitcoin.com

https://uk.godaddy.com/domain-value-appraisal/appraisal/?checkAvail=1&tmskey=&domainToCheck=bitcoin.com  - $25,000

https://www.freevaluator.com - $ 181,471.65