Before purchasing a domain name it is best to perform a trademark search, on a tag line, domain name, and / business name that you plan to use; since you do not want to infringe on the intellectual property of a company. It might seem difficult to believe, but some businesses actually own the right to certain key words, terms, phrases, slogans and concepts. There are upwards of 250 domain extensions. Also, there is a vast list – ranging upwards, to 70 or more – of abbreviations for the domain name industry.
Some currently listed high-priced domains, at auction, fetch upwards of $185K to more than $35 million dollars.
Some of the Highest-Priced Domains:
- VacationRentals.com $35 million in 2007
- Insure.com $16 million in 2009
- Fund.com 2008 £9.99 million
- Business.com for $7.5 million in1999
- Diamond.com 2006 $7.5 million
- Beer.com 2004 $7 million
- Israel.com 2008 $5.88 million
- GiftCard.com by CardLab for $4 million in 2012
- Yp.com by YellowPages.com for $3.8 million in 2008
- AltaVista.com for $3.3 million in 1998
- Candy.com for $3.0 million in 2009
- Loans.com by Bank of America for $3.0 million in 2000. 
Before buying a domain one can have its value appraised. Be cautious as to which domain appraisal website you use, as some are more accurate than others. While some evaluators utilize key word frequency and balance these against the number of searches on the phrase, others assessors are totally arbitrary and the valuation is unreliable.
Recently Registrars on the Internet began releasing the first batch of nearly two thousand new domain extensions; including everything from dot beer to dot health. Any combination of phrases and keywords is possible within the domain name and as combined with the extension.
The release of these domain extensions is due in part to hoarding of domain names and trademark infringement. Many domain entrepreneurs bought up many domain names that represent and express the brand of an existing business, with the intention to sell the same domain name to the business whose name is part of the domain name.
Many small, medium and large business owners and corporations complained about this seeming injustice, while being unwilling to pay the sought after price to acquire there a domain name that contains their own business brand. In the past businesses could complain to the United States Congress, which used to monitor and regulate the Internet. Now the Internet is managed by a consortium, known as the Madrid Conference, which is supposed to be organization operating as an independent entity and totally separate from any government jurisdiction, but which is seemingly accountable to the United Nations.
New domain extensions and new domains registered at same are now monitored and processed through a clearinghouse that accepts trademark registrations and holds or blocks potential domain registrations, which may infringe on said trademark.