Link Valuation Technique - PageRank Table

In an effort to better identify good linking opportunities, I decided to figure out a method of comparing the values that certain links hold. Of course a PR4 link is worth more than a PR 0 link, but how much? And is it worth it to build a PR4 link as opposed to a bunch of PR 0 links? Why or why not?

Here is the way I look at PageRank. This is based on the information in Google's patent for PageRank. I didn't come up with this PageRank Table myself, but I use it a lot for valuing links. Google the term "PageRank Table" for more information on how the table was devised.

PR Value
0 1
1 5
2 25
3 125
4 625
5 3125
6 15625
7 78125
8 390625
9 1953125
10 9765625

I basically give a PR 0 link a value of 1. So a single PR 0 link = 1. A PR1 link is worth 5 times as much as a PR 0. A PR4 link is worth 625 times that of a PR 0 link, etc., and PR10 link is worth 9,765,625 PR 0 links.

Then I think to myself, would I rather build 625 low quality PR-/0 links (many of which will never even be crawled/indexed/cached/counted) or should I build the equivalent to that, which is a single PR4 link. Well of course I'm going to build that single PR4 link. It's much easier, takes much less time, and is much more likely to be found and counted.

Now this table may not be perfect, and sure, there are other factors to take into consideration when using it, such as "indexed" age for the page and outbound links on the page (I don't get too worried about OBLs if there are less than, say, 100 links on the page), but I mainly just use this table to get a quick estimate of how much links are worth when comparing PR and determining whether certain linking opportunities are worth the time and effort.

Another use for this table, though, is in determining how many link value "units" you will need to build to your site in order to claim the top spot in Google for your keyword. Basically, all you do is look at your top competitor's backlink profile using a program like SEO SpyGlass. Then, add up the link values of each of their backlinks. For example, say your competitor has three PR2 links two PR3 links, a PR4 link, and a PR5 link. That's (3x25)+(2x125)+625+3125 = 4075 total link units. So in order for you to take over that top spot, you need to build links that equal or surpass a link value of 4075. So you need 4075 PR 0 links, or 815 PR1 links, or 163 PR2 links, or about 33 PR3 links, or about 7 PR4 links, or any combination of links who's link values total, well, 4075.

Again, this isn't 100% perfect due to other ranking factors and whatnot, and I'm totally aware of that fact, but it will definitely give you a good idea of the amount of work you'll need to do to rank for a given term.