Link Weight

My homepage is now a Google PR 6. Many of my pages are PR 5s (including pages like "Contact us" and "privacy statment" but thats another question). Some are 4s. Some are unranked.

Question: Whats the relative benefit for me to getting more links from 0's? 1's or 2's? 3s or 4s? 5s? 6s? 7s? I think the algorithm probably depends a bit on the base that you are starting from and your current rank. For me, I have several hundred relevent links in including a about a dozen 5s and 6s.

Heres my theory. For me, assuming relevency:

a link from a PR7 is worth 5x a PR6
PR6 is worth 5x PR5
PR4 is worth 5x PR4
PR3 is worth 5x PR2
PR2 is worth 5X PR1
PR1 is worth 5X PR0

I would be pleased to hear other theories, particularly if they are based on more solid analysis than my own......

My site: interactive homeschool curriculum