depends those sites maybe will become pr7 in a couple of years ! i don't understand why people don't link to pr0 anyway ! because maybe the site is pr0 now . but if the person who owns the site works hard that pr can grow ... and you both are winners !
There is almost no such a thing as a pr 0 link. Every link has a value of like 0.34 or 0.45 or 1.23 but you have to reach the pr update to see them. However, the google algorithm takes into account the real value of the pr of the link, not the one that is displayed in the toolbar.
Also dont just look at the toolbar pr and decide use a tool like dnscoop to look at all the variables, # of backlinks being an important one.