Domain age effect in seo.

If you are interested in seo and started to read how to do perfect seo job, you may have heard old domain name have a good effect in seo process. but how much?
In my opinion, if you have a old domain name, use it ( if it match your business). otherwise go for a fresh new name. this helps to build a brand. buying a old domain name is not a good idea at all. Because you don't know how it was used? is it good with the search engine?
Registering a new domain name for long time Replaces the need to buy a old ( aged) domain name or having a old one. because registering the domain for long time send very good signal to the search engine that this domain name is here to stay and is not registered for spam purpose. search for a available domain name