backlinks from subdirectories

I have several backlinks from different subdirectories of a website.

These subpages have google pr5 or pr6. The domains itself has pr8.

If I make a lot of these backlinks to one website, does that have the same value as if the subpages were independent domains?

No, some value but not the same weight if the links had come separately from different domains or IPs. Look at Traffic Travis and they track this info.

See, when it comes to backlinking, we are talking about web pages... A page is more important that its domain, no matter whether its coming from directory or sub directory. If you are getting backlinks from a page having PR 6-7, I believe this is good enough. The only thing to be consider is relevancy of the pages.

As far as backlinks from sub-directories are concerned, they are considered as internal links.