I would pay anywhere between 0 to 100, and PR is definitely not the major criterion.
See if -
The page that lists you ranks well for terms that it apparently promotes.
The site is online for atleast 2 years (My personal benchmark)
A significant % of its pages are empty - Not good.
Editorial quality. Whether your closest competitors are listed in the page you will be listed, or are they thinly related.
The directory runs other sites with same content.
If the directory uses any SE or dmoz feeds to populate the pages.
In my opinion, PR and price aren't the best metrics to use. Do a whois inquiry on them and check if they have sister directories sitting on the same ip. Check their backlinks in Yahoo, checking for quantity and variety.
I wouldn't list just based on PR either. Remember PageRank does drop in during updates, and then what are you left with.
Is the entry for life or do they charge per year?
Mind you if the site is very useful and established, $25 seems very good value - even that rate paid every year is worth it, as long as the traffic is there.
Since you're asking about PR, I'll respond you about PR:
For $25.00 a lifetime PR5 link is very good.
Keep in mind that it's the PR of the page your link would actually be on that is significant, not the PR of the home page.
Do a site command in G for that directory and see if any submitted listings have been indexed. If not, it means that the listings cannot be crawled or the directory is very new.
For me, I am more interested in the amount of traffic the link will generate. PR is just gravy. I'm always looking for traffic levels first. Just my opinion, but I think many are "PR Clouded" when doing campaigns.
I still find the most important aspect of a directory is who they are linking to. Does your category link to all your competitors? Is it detailed to fit your niche? Or is it extremely vague and features sites completely non-relevant on the page?
If the page is cached in Google, then yeah, it's probably worth it.
PR is not the factor to look at these days.
> PR is not the factor to look at these days.
Maybe the PR showing in the toolbar...
For my experience PR is still very important.