Pleas tell me How to buy second hand PR(page rank) domains?
Impossible to do as you asked.
Domains are neither “SEO friendly” nor “Page Rank”, pages are.
Can you rephrase to better explain what you mean?
As @Mittineague said, it can’t be done; your question is based on a misunderstanding.
PageRank is calculated per page, not per domain, and is based solely upon the number and quality of incoming links to that page.