As Google is all about "quality", logic dictates that a link from a "8-quality" site is more important than a link from a "1-quality" site.
But......... a link from a "1-quality" Belguim site about dolphins to a Belgium site about whales will be more important than a link from a "8-quality" site vvvvvv.big-boobies-for-boys.co.us to the Belgium dolphin site. Relevance is becoming more important, and most of the links from "high pr sites" that are fore sale, are of no relevance at all, and will therefore do little to boost the serp position.
On top of that, both pr and link imporance are on the decline and the import of the question is more theoretical than practical. Several of my pages with pr=0 and 0 backlinks, still rank top in serps, purely due to relevance and content.
Pr and artificial backlink strategies are old hat and are not worth spending time on unless you have a budget that allows to squeeze out every last tenth of a percent of seo juice.