Private networks blogs page rank

Hi guys, I am building a network of blogs (already have around 80). Until now i have focused more on quality domains with links/pa/da and a bit of pagerank. I read somewhere that instead of paying say 200$ for a really good PR3 domain name with links/authority you better buy 5-10 pr1+ expired domains, cheap, even if they do not have any links/authority...

The explanation was that it is always better to have 6 medium quality links rather than a good, strong one.

Bullshit or not?

well, one great backlink is always good to have and probably it has been better than several low quality ones in the past, but nowadays a diversity of backlinks is required, so not quite sure which is better nowadays..

Well that is what I am wondering as well....