I'm planning on building a site in a national competitive niche.The thing is,the first 3-4 websites all of them haves PR higher then 2 and 2 years+ of age. I was thinking to buy a new emd and an old aged one with some PR. When should I redirect the old one to my new emd? As soon as i make the purchase,not even index the emd or add content,or should I index the emd first,add some articles and then do the 301 redirect from the old domain? As I know,this should give my new site some age and PR,maybe some link juice if i'm lucky,but i don't know the propper moment to do it.