People shoudnt obsess about page rank at all. The most important thing is not your page rank but your position for your selected keywords and phrases. I provide a service for SEO Dundee and I have seen great success for 99% of clients without ever considering page rank for a minute.
I really dont get why people still care about page rank.. You should care more about your SEO and how many people buy your stuff. You can have a mega page rank of like 8 and still make no money from your website. I currently rank 11th for SEO Dundee but first for almost all of the main search terms i need. The rank of my SEO Dundee page is 1.