You can sell domain name in any domain name auction sites.Like sedo,ebay etc. before sell domain name you can know the age of the domain name.Because Domain name age is important factor in SEO.But 14 years or 8 years is not matter.A website with 1 year with low traffic,no quality backlinks will not be indexed soon in search engines.But if domain name with good seo ,but 6 months aged having huge visitors,quality backlinks will indexed soon in google.So age is important,also links,traffic,visitors ratio more important for domain name in seo point of view.Domain name age can be calculated by domain name expiration or current date minus from domain name registration date.If a domain name expire on may-28-2013 and registered date is may-28-2012.The age is exactly 1 year.To check domain name registration and expire date you can visit the site
www.whoisxy.com .