I find it hard to get above PR5.
How do you get PR6+

Ive tried so many things but nothing seems to work.

Well the concept is simple - get links from PR7 and above websites.
Thats hard to do though, they can charge quite a lot for that but you need to decide if its worth it or not.
Usually it is

Look at where the big high PR sites are getting links from.
I bet they are from authority sites. Thats where you need to look, its hard to partner with those sites though.

how much will i need to pay for links on those sites?
Any idea? Im guessing it wont be cheap.

Pay $100+ for some top links and you will see the value in spending that much money.
I do it, hence my PR7 site

$100 for a link? Wow..

Is that a permanent link or a monthly fee?