Matt Cutts, Google spokesman for SEO, argues the age of your domain name is a factor Google takes into account when ranking your website. However, domain age is not really that important. Google’s algorithm observes how old your domain is from how long ago that domain had content on it. ECreative argue once your domain gets past the first few months of age it will not matter much whether it is 6 months old or 1 year old.
Sean at SEO Hacker found, with exactly the same content on a 7 year old and a 3 year, old domain, the 7-year-old domain ranked higher on Google. This is a similar scenario for some of the tests we have run. To be more specific we ran 7 tests for various different domains and found that between a the domain and a 4 month old domain there were generally weak results. However, once we at Team Discovery tested between 6 month and 5 year old domains there was only a very minute difference in ranking (+/- 2 positions).
From the research we conducted we would suggest two things. Firstly, at the earliest stage of your website construction you should get content on your domain (so as to start utilizing this small factor early on). Secondly, you should not worry about buying old domain names for the sake of OLD domain names.