I am sure that this has been answered before, and I read the sandbox FAQ (Very nice post) and it said there is no way round it. If I have a site that is 3 months old, and I buy a domain that is say 12 years old and relative to my current site, then I host that new domain on a diff IP (Different continent in fact) and use a 301 redirect. Would this not signify to the googlebot that this prestigious domain has now moved, and it is infact this new site, and hence, this new site must be trust worthy? And if that would not work, is there any benefit in buying a 12-15 year old domain and using a 301 redirect?
I wouldn't buy an old domain and redirect it to a new site. It can trip a filter will google (they are not stupid). You would be better off buying an older domain that was relevant to your current site and redirecting the new to the old. If you buy an old domain, make sure it has archived history dating back quite some time. Google counts domain age from when it was indexed, not when it was created and never used. Buying an old domain that was parked and then redirecting it to a new domain would not give you any benefit imo.
From my experience, this will not help at all. Developing an older domain that has already been indexed does seem to find its way into the SERPs faster...
This would be a massive job because so long story short is dont bother. Thanks for your help, saved me about $700.