I would say reg fee for all of them because there isn't really a point to them. I don't see their content to being of any value.
But what kind of site would you put to it? I don't see the value either unless you were trying to demo fake pagerank...In which case you should have bought 8,9, and 10
For pagerank 4 link .com you will get list of page rank 4 sites? and will exchange link with only page rank 4 sites? For pagerank 5 link .com you will get list of page rank 5 sites? ...... all domain names are confusing, and lack of any development idea. So reg. fee will be enough
At first, I would like to thank you all. I think link exchange and link trade would be new hot fields. So I think these domain is useful for link exchange and link trade.