I see a lot of expired domains(still indexed by google) with PA-50+, DA-50+, over 10k backlinks. Most of the backlinks are blog comments but there is still a lot of link diversity on some domains. Price is usually from $5 to $11 + 1 year renewal $9 for a domain like this. So, about $15-$20. From what I see, most of them are abandoned because of low keyword diversity - Penguin. Let's say I buy one domain, I put 1-2 unique articles fro my niche and place a strong backlink on the homepage for my money site. Is this "strategy" any good ? What is the value of a "strong domain" after is expired ?